WELLCAT GUIDE MATERIAL WELLCAT Overview WELLCAT (Well Casing and Tubing) is an integrated suite of programs that both predict temperatures and pressures in the wellbore and analyze stresses and deformation (including buckling) in tubing and casing. WELLCAT makes it possible for you to perform the following essential tasks:
Accurate temperature modeling
Reliable service life analysis
Critical well design
Complex tubular stress and movement analysis
MultiString analysis
WELLCAT’s WellStress-Casing (Casing) is used to analyze casing loads, design integrity, and buckling behavior under complex mechanical, fluid pressure, and thermal loading conditions. It has standard and automatic loadcase generation, is linked to Drill or Prod thermal analysis, and is an advanced Windows-environment engineering tool for
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Comprehensive casing design and analysis Installation and service load analysis
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Multi-string load transfer analysis
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Buckling stability and post-buckling analysis
Casing has the following features:
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Determination of running, installation, and service loads and stresses from standard or automatically generated user-defined load cases Determination of accurate load, stress, and buckling solutions for both vertical and directional wells, with or without friction
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Consideration of all mechanical, fluid pressure, and thermal loading mechanisms
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Specification of separate design factors for pipe body and connection
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Determination of burst, collapse, axial, and triaxial safety factors, with burst and axial safety factors based on lesser pipe body or connection ratings
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Accommodation of user-specified yield anisotropy for CRA or composite materials applications
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Accommodation of user-specified temperature-dependant yield strength and user-specified-minimum wall thickness (API default)
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Evaluation of annulus fluid expansion due to heat-up during drilling or production, and determination of required bleed-off volumes for control of collapse and burst loads
WELLCAT’s WellStress-Tube (Tube) is used to analyze tubing loads, design integrity, and buckling behavior under complex mechanical, fluid pressure, and thermal loading conditions. It has standard and automatic load-case generation, is linked to Prod thermal analysis, and is an advanced Windows-environment engineering tool for
Comprehensive tubing design and analysis
Installation and service loads
Tubing movement
Complex completions
Buckling
CRA tubulars with yield anisotropy
Tube has the following functional features:
Determination of installation and service loads and stresses from standard or automatically-generated user-defined load cases, including production, injection, shut-in, tubing leak, pump-in to kill, rod pump, pressure test, fracture screen-out, full evacuation, and overpull during installation
Determination of accurate load, stress, and buckling solutions for both vertical and directional wells, with or without friction
Accommodation of multiple mechanical or hydraulic-set packers and dual-completion hook-ups
Specifications of latchdown and sliding tubing-packer seal assemblies, with user-specified up/down displacement and no-go constraints
Consideration of all mechanical, fluid pressure, and thermal loading mechanisms for all load cases
Specification of separate design factors for pipe body and connection
Determination of burst, collapse, axial, and triaxial safety factors, with burst and axial safety factors based on lesser of pipe body or connection ratings
Accommodation of user-specified yield anisotropy for CRA or composite materials applications
Accommodation of user-specified temperature-dependant yield strength
Evaluations of annulus fluid expansion due to heat-up during drilling or production, and determination of required bleed-off volumes for control of collapse and burst loads
WELLCAT’s WellTemp-Drill (Drill) is used to simulate fluid flow and heat transfer during drilling operations. It has full transient analysis, linked analysis with Casing, and is an advanced Windows-environment engineering tool for predicting
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Cementing temperatures HPHT hydraulics
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Downhole tool temperatures
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Casing service loads during drilling
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Undisturbed temperature profile from log data
Drill has the following functional features:
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Modeling of thermal disturbances due to drilling from input of drilling days, rotating hours, and average flow conditions Correction of drilling fluid, cement rheology, and density for downhole temperature and pressure
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Modeling for deviated and offshore wells
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Determination of undisturbed temperature profile from log data
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Determination of circulation temperatures, pressures, and effective circulating densities for drilling, hole conditioning, and cementing operations
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Modeling of casing and liner cementing, cement squeezes, and cement plug settings
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Calculating slurry placement temperatures and temperature build-up, start to finish
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Determination of post-cementing casing temperatures for landing, and casing temperatures during drilling of deeper intervals
WELLCAT’s WellTemp-Prod (Prod) is used to simulate fluid flow and heat transfer during completion, production, simulation, testing, and well-servicing operations. It has full transient (or steady-state) analysis with Tube and Casing, and is an advanced Windows-environment engineering tool for predicting
Temperatures and pressures for flowing and shut-in well-streams Conditions for tubing analysis based on service loads
Temperatures and pressures during forward and reverse circulation
Thermo-setting resin and gel treatment behavior
Permafrost thaw radius
Prod has the following functional features:
Modeling, in series, of linked productions and non-production periods, including circulation and injection operations, to build an accurate chronology of wellbore thermal variations Modeling of compositional (black-oil), VLE, and file-defined hydrocarbons as well as water-based and oil-based drilling fluids, brines, foams, cements, and reactive gel treatment fluids
Analysis of multi-phase flow using standard industry correlations (Beggs & Brill, Duns and Ros, Gray, Hagedorn & Brown, Orkiszewski, Zhang Mechanistic, Kaya Mechanistic, or Ansari Mechanistic)
Analysis of gas PVT behavior using standard industry equations-of-state (Benedict-Webb-Rubin, Soave-Redlich-Kwong, Soave-Redlich-Kwong-Starling, and Peng-Robinson)
Modeling of temperature and pressure dependence of density and viscosity for water-based and oilbased drilling fluids
Consideration of all casing strings and annulus fluids in thermal analysis, and provision of temperatures at all significant radial positions
Analysis of bottomhole pressure build-up behavior for shut-in gas wells
Calculation of time-domain variations of fluid pressure and properties in transient analysis
Analysis of permafrost thaw and freezeback behavior
Modeling of gel-injection operations, with radial tracking of gel front in permeable layers
Analysis of coiled tubing-aided well servicing operations
Inventories Menu Inventories are provided to supply information for populating fields in spreadsheets and dialogs when defining a well file. The template file used to build the well file provides default values contained in the inventories. Once a well file is saved, the data contained in the Inventories at that time are saved with the well file.
Click a command for a description. • •
Tubing Filters Fluids
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Pipes
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Drill String
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Heat Conduction Properties
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Coiled Tubing
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Grade Properties
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Drill String Grade Properties
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Temperature Deration
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Proprietary Connections
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In-House Connection Test Data
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Bit Sizes [Hole Size]
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Formation/Soil Properties Spreadsheets
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Cement Properties
Tubing Filters This option is available when the Pipes, Drill String, Coiled Tubing, and Proprietary Connections options on the Inventories menu have been selected.
Click a command under this submenu for a description.
OD Filtering
Sorting
Select Pipes
Fluids Inventory Dialog (Inventories > Fluids) The Fluids Inventory dialog uses several tabs to specify fluid characteristics you can use to build fluid models.
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Brines Cement Slurries
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Compositional Muds
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File-Defined Hydrocarbons
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Foams
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General
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Polymers
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Standard Hydrocarbons
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Standard Muds
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VLE Hydrocarbons
Brines Tab (Fluids Inventory Dialog) (Inventories > Fluids> Brines tab)
Use the Brines tab to specify basic clear brine characteristics. The model determines temperaturedependent and pressure-dependent density and viscosity. The program provides default values based on common field practices. For CaBr2 brines, the default assumption is that the brine is generated by mixing 11.6 ppg CaCl2 brine with 15.1 CaCl2-CaBr2 brine. This minimizes the amount of CaBr2 in the brine. A similar technique is used for ZnBr2 brines where 19.2 ZnBr2 mixed brine is combined with 15.1 CaCl2-CaBr2 brine to obtain the desired density. As an alternative, if viscosifiers or solids are added to clear brine, the program’s water-base drilling mud model should probably be used in order to accurately model the fluid rheology. Use the Inventories > Fluids > Compositional Muds tab. The program displays the default fluid seawater. You can define your own characteristics using the fields provided. Click an item for more information.
Fields and Controls Name This field is used to specify a unique name for a fluid. Either type a name into the list box or let the program provide a default name. Comments You can record your own notes about the fluid or analysis you are currently defining. Enter comments into this field as you do using any text editor. Type and Density Specify the type and density of the brine (The program automatically uses the value you specify for one to provide the other). These are the minimum and maximum densities allowed for the brine types. Brine Type
Seawater KCl NaCl CaCl2 CaCl2CaBr2 CaCl2CaBr2ZnBr2
Minimu m Density (ppg) 8.33 8.33 8.33 8.33 11.6
Maximu m Density (ppg) 9 9.8 10 11.6 15.1
15.1
19.2
Rheological Temperature This field specifies the temperature at which the rheological properties of the Brine tab are measured. The default temperature value for brines is 70° F. Fluid Expansion This drop-down list box shows the choices available for specifying fluid expansion behavior. When you choose PVT Table, you can click the Properties command button to access the PVT Table Properties dialog so you can specify values or import a file containing the PVT values. Properties button
This button is available when you select PVT Table from the Fluid Expansion drop-down list box. If you click the button, the PVT Table Properties dialog appears with a tabular spreadsheet so you can specify values or import a file containing the PVT values. For additional information, see PVT Table
Properties Dialog.
Pipe Inventory Spreadsheet (Inventories > Pipes) Use the Pipe Inventory spreadsheet to define the inventory of available pipes. When this spreadsheet is accessed for the first time, it will display an inventory of pipes with an OD that corresponds to the currently specified Select Pipe OD. To change the displayed OD, select another OD from the toolbar's Select Pipe OD drop-down list box. Alternatively, select "All" to display every pipe in the inventory. The inventory is automatically sorted on keys specified in the Sorting dialog. To be considered a valid entry, every cell in a row must contain a value. By default, the initial contents of the Pipe Inventory spreadsheet for a given well file are identical to the contents of the Pipe Inventory for the template file that was selected. However, immediately after the well file is created you can add, modify, and remove entries as needed. The only entries that cannot be modified or removed are those that are currently included in the design of one or more strings. To expedite the entry of new pipes, if you first select a row and then insert a row, a row identical to the selected one will be inserted into the spreadsheet except that the Grade field in the new row is left blank. This eliminates the need to re-enter a large amount of duplicate data. To quickly highlight multiple rows using OD, weight, and grade criteria, use the Select Pipes dialog. You can copy rows from this spreadsheet using the Copy command and store them in the Inventory library with the Paste command. This allows you to easily move and re-use inventories between well files, since libraries act as permanent repositories of frequently used data.
Columns OD This value must be > the value for Drift in the entry. It also must be > the value for ID and < the value for Hole Size. Weight Specify the nominal weight per unit length of the pipe. This is the API value appropriate for the OD specified. Grade or Name Specify the grade representing the pipe’s yield strength. For example, N-80 is 80,000 psi yield strength. Enter a value or double-click the cell for a drop-down list box displaying the appropriate values available. ID Nominal ID of the pipe. This is the appropriate value in the file PIPECTLG.DAT for the OD and Weight you specified. If the file does not contain the OD and Weight, the program calculates the ID value. Type Double-click the cell for a drop-down list box listing the following pipe categories: Rating Wanted
Drift Diameter Wanted
Value to Select
Not standard API
Not Standard API
Special
Standard API
Not Standard API
Standard
Standard API
Standard API
Min API
Drift Specify the internal drift diameter of the pipe. You must have selected Standard or Special in the Type drop-down list box. This value must be ≤ the ID value. The default value is the value for the pipe in Table 5.1 of API specification 5CT (Identified by the values for Pipe-OD and Pipe-Weight). Ratings Burst Burst performance rating for the pipe. Ratings are calculated using the internal yield for pipe formula in Section 4.1.1 of API Bulletin 5C3. Collapse
Collapse performance rating for the pipe. Ratings are calculated using the collapse pressure formula in Section 2 of API Bulletin 5C3. Axial Axial performance rating for the pipe. Ratings are calculated using the pipe body yield strength formula in Section 3.1 of API Bulletin 5C3. Critical Dimensions Define the percentage of pipe wall that will be used for stress analysis for burst, collapse, axial, and triaxial designs. You can globally change ratings by using the Change Critical Dimensions command. Burst Specify the percentage of the burst stress rating to be used in the stress analysis. Collapse Specify the percentage of the collapse stress rating to be used in the stress analysis. Axial Specify the percentage of the axial stress rating to be used in the stress analysis. Triaxial (Longitudinal and Hoop) Specify the percentage of the wall thickness to use in calculating the principal stresses (longitudinal and hoop) used in the VME calculations. Triaxial rating for the pipe is the yield strength specified for the particular grade on the Grade Properties Spreadsheet . Plain End Cost Cost per unit of length for the pipe. This cost does not include connections. For default values, cost is calculated using the price of K-55 steel (Tools > Options > Engineering tab). This spreadsheet is never included in the Wizard list.
Drill String Inventory Spreadsheet (Inventories > Drill String) Use the Drill String Inventory spreadsheet to populate the choices available on the Drill String tab used for Drill operations. Three types of drill string components can be specified: drill collars, drill pipe, and heavy-weight drill pipe (HWDP).
Columns Type Three types of drill string components can be specified: Drill Collars, HWDP, and Drill Pipe. OD Specify the outside diameter of the drill string component (Type) being defined. Weight Specify the drill string weight on a per unit length basis, including the weight of the connections. Grade or Name Grade or Name is not required for drill collars, since it does not apply. For drill pipe and HWDP, type in a single letter. If that letter does not correspond with a grade in the DP grade inventory, a drop-down list box is enabled. Select one of the characters in the drop-down list box, or select the Inventory option to create a new entry in this inventory. ID
Specify the drill string inside diameter.
Coiled Tubing Inventory Spreadsheet (Inventories > Coiled Tubing) Use the Coiled Tubing Inventory spreadsheet to populate the coiled tubing geometry spreadsheet used in Prod Operations. If an operation has been defined in Prod with a coiled tubing configuration specified in the Operations dialog, a Coiled Tubing Geometry tab is available after clicking the Details command button. The spreadsheet on this tab must be populated in order to calculate this operation. All Coiled Tubing Inventory spreadsheet data are entered in free-form text. These data are not linked to other inventories. Columns OD Specify the OD of the coiled tubing. Wall Thickness Specify the thickness of the coiled tubing wall. ID Specify the ID of the coiled tubing. Heat Conduction Properties Select the material or alloy that the coiled tubing is made of from the drop-down list. Double-click to display the drop-down list. Only materials or alloys specified as structural materials on the Heat Conduction Properties Spreadsheet will be listed. Weight Specify the weight of the coiled tubing on a per unit length basis.
Grade Properties Spreadsheet (Inventories > Grade Properties) Use the Grade Properties spreadsheet to specify the grade and mechanical properties for the strings defined in a well file. Columns Name Name of the grade whose properties are being specified. No two entries should have the same name, but the software does not strictly enforce this. Yield Specify the Minimum yield strength for the grade or material. It is used to calculate the ratings for pipes and tubing connections. Its value must be ≤ the value for UTS. Stress is the parameter in the Unit System.
UTS WELLCAT uses the ultimate tensile strength (UTS) to calculate the fracture strength for API connections. This is the minimum ultimate tensile strength for the material. Its value must be ≥ the value for Yield. For a default value, the program provides the appropriate value for the grade (Provided only if the grade is standard API.). Stress is the parameter in the Unit System. Young's Modulus This cell contains the Young's modulus of the material from which pipes of this grade are made. For an elastic material, Young’s modulus is one of two independent parameters (the other is Poisson’s ratio) that describe the mechanical behavior. It is defined as the ratio of stress and strain. The default value is 30,000,000 psi, which is the value for steel. Young’s Modulus is the parameter in the Unit System. Poisson's Ratio This cell contains Poisson's ratio of the material from which pipes of this grade are made. For an elastic material, Poisson’s ratio is one of two independent parameters (the other is Young’s modulus) that describe the mechanical behavior. When a cylinder is pulled in tension, it contracts radially as well as elongates. The ratio of the lateral contraction to elongation is called Poisson’s ratio. For pipes, it relates lateral contraction to axial elongation, and also axial contraction to internal pressure. The default value is 0.3, which is the value for steel. Thermal Expansion Coefficient Specifies the coefficient that characterizes the unit change in length with a unit change in temperature. Its default value is 6.9E-06/deg F, which is the value for steel. Thermal Expansion Coefficient is the parameter in the Unit System. Anisotropy The radial and hoop yield factors of the material from which pipes of this grade are made. For certain pipe grades, the yield stress may not be the same in all directions. In this case, the yield stress is based on the axial yield stress, and factors are used to reduce the yield in the radial and hoop directions. The default value is 100%. Temperature Deration Select the desired temperature deration schedule from the drop-down list. Use the Temperature Deration Spreadsheet to define the temperature deration schedules. A schedule must be defined using the Temperature Deration spreadsheet before it is available for selection on the Grade Properties spreadsheet. Heat Conduction Properties Select the material or alloy that the grade is made of from the drop-down list. Double-click to display the dropdown list. Only materials or alloys specified as structural materials on the Heat Conduction Properties Spreadsheet will be listed. Cost Factor Cost factor (multiplier) for the grade or material in relation to API K-55 steel. The cost factor for K-55 steel is 1.0. The default values used are the grade and mechanical properties from the template selected when you created the well file.
Drill String Grade Inventory Spreadsheet (Inventories > DP Grade Properties)
Use the Drill String Grade Inventory spreadsheet to create a new entry for use in the grade field of the Drill String spreadsheet. 1.
Select either Drill Pipe or HWDP in the Type cell, and then enter a letter in the Grade or Name cell.
2. In the Heat Conduction Properties cell, select the material or alloy that the grade is made of from the drop-down list. Double-click to display the drop-down list. Only materials or alloys specified as structural materials on the Heat Conduction Properties Spreadsheet will be listed. 3.
Close the spreadsheet.
4.
The Grade or Name you created is now available for selection by double-clicking the Grade or Name cell.
Columns Type Double-click and select one of the following drill pipe options: Drill Pipe, or HWDP (heavy-weight drill pipe). Grade Specify the grade of the material for the drill pipe or HWDP by typing in a letter for the grade. Heat Conduction Properties Select the material or alloy that the grade is made of from the drop-down list. Double-click to display the dropdown list. Only materials or alloys specified as structural materials on the Heat Conduction Properties Spreadsheet will be listed.
Temperature Deration Spreadsheet (Inventories > Temperature Deration) Use the Temperature Deration spreadsheet to specify the temperature deration schedules for grades by specifying temperatures and their associated yield correction factors. When you first use this spreadsheet, the default entry, Default Schedule, appears. This entry consists of two sets of points that represent a linear reduction in yield strength of 0.03%/deg F.
Columns Name Specify a unique name for the schedule. Default Schedule is provided as a default name. Point A series of pairs of two cells each that show the correction factor for the yield strength and its associated temperature. Temperature is the parameter in the Unit System.
Wellbore Menu This menu has commands used to display the well schematic and specify wellbore properties.
Click a command for a description.
General
Offshore
Wellpath
Dogleg Severity Overrides
Undisturbed Temperature
Lithology
Casing and Tubing Configuration
Annulus Contents
Buckling Restrictions
Packers
Liner Isolation Packers
Current String
Well Schematic
Cementing and Landing
Pore Pressure
Fracture Gradient
Squeezing Salt/Shale
Hole Profile
Operations Menu Drill and Prod have different commands available under the Operations menu.
Click a command for a description.
Operation Times (Drill)
Drilling Operations (Drill)
Operations (Prod)
Drilling Operations Dialog (Tools > Select Product > Drill, then Operations > Drilling Operations) Use the Drilling Operations dialog to specify the name for an operation and essential values (such as operation type, hole section, or pipe) that will be modeled by the operation. The selections you make in this dialog determine the tabs that will be available in the Drill Operation Details dialog for you to complete data entry for the drilling operation. The Run on Drill String? check box may not be present on your dialog. For it to appear, you must have Subsea selected as the well type location on the Wellbore > General dialog, and Primary Cementing or Run Casing String & Circulate must be selected as the operation type on the Drilling Operations dialog.
After making your selections, click Details to access the Drill Operation Details dialog so values for the specific drilling operation can be completed.
Fields and Controls Operation Name A user defined name for the current operation. Highlight a field and enter the name. To change a name, click the field containing the name once and type the new name. Operation Type Contains a list of all possible drilling operations in WELLCAT. To use Drill productively, define operations in the order that they would naturally occur during the well drilling process. Prior Drill Operation The prior operation to which the current operation will be linked. The current operation will obtain its initial temperature conditions from the prior operation selected here. This is a desirable feature when modeling drilling operations that are sequential in order so that the well temperature history can be accurately tracked.
Next Casing String Defines the next string to be run into the well for all operations. For Run Casing and Circulate, Primary Cementing, Squeeze Cementing, and Spot Cement Plug Operations, the Next Casing String selection should be the string that the operation will be performed on. Hole Size This field corresponds to the next casing string specified in the Next Casing String field. This value is populated from the Hole Size cell for the Next Casing String in the Casing and Tubing Configuration spreadsheet. Riser Present Mark this check box to display the Riser Geometry tab on the Drill Operation Details dialog. This check box is only available for subsea and platform wells. Copy Op button Use this button to copy a previously defined drilling operation as a new operation with the same input parameters. The new operation can be renamed and the input values modified to develop a unique drilling operation from a previously defined drilling operation. To use this feature, highlight (select) the operation to copy and then click Copy Op to create a copy at the end of the Operation Name list. Run On Drill String? Mark this check box to display the Drill String tab on the Drill Operation Details dialog. This check box is only available for subsea and platform wells when the current operation is Primary Cementing or Run Casing & Circulate. If the check box is marked, the Casing is modeled as being run on drill pipe. It is otherwise modeled as run on casing with the same OD, weight, and grade as the Next Casing String.
Operations Dialog Tools > Select Product > Prod, then Operations > Operations Use the Operations dialog to specify the name for an operation and essential values, such as the type of operation for the flow path(s). The selections you make in this dialog determine the tabs that will be available in the Operations Details dialog for you to complete data entry for the operation.
Fields and Controls Name A user-defined name for the current operation. Highlight a field and enter the name. To change a name, click once on the field containing the name once and type the new name. Configuration The selection made from this drop-down list box determines the values used in the Operations group box. Riser Present Marking this checkbox specifies that a riser is in place during the operation This check box is only available if
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Subsea was selected from the Location drop-down list box in the General > Description tab
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Production Tubing was not selected from the Configuration drop-down list box in this dialog (applies only when the tubing string MD-Hanger value is ≥ the MD that corresponds to the mudline TVD).
If a MD-Hanger value was specified for the production tubing that is < half the mudline depth, the following actions are automatically taken:
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The check box is automatically marked and cannot be unmarked. A tension leg platform well is modeled with a riser, production casing, and production tubing going up to the platform at the surface.
When Workstring, Coiled Tubing, or Tubingless are selected from the Configuration drop-down list box, this check box is automatically marked as a default. Operations Specify the operation type and fluid for the flow path(s) for the configuration. For example, if the current string is 3 ½" production tubing, and Production Tubing is selected for the configuration, the program automatically displays 3 ½" production tubing in the spreadsheet’s first row and annulus in the second. Selections made influence the remaining selections on the Operations dialog and the tabs available in the Operations Details dialog. Type and Fluid have drop-down list boxes.
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Type contains all operation types supported by the program, such as production, injection, and cement squeeze. Fluids contains fluids appropriate for the selected operation. A steam injection operation is defined by specifying Injection as the Operation, and selecting Wet or Dry Steam as the fluid.
Dual Injection: Dual injection is available for Steam injection and some coiled tubing operations. For all other injection operations, the second flow path is shut-in. Steam Injection Operations: If you select Steam Injection in the tubing and the annulus, the two injection operations are independent of each other, and no pressure communication at the well bottom is supported. If desired, you can manually iterate the injection conditions in one of the flow paths to achieve equalized downhole pressures. The Steam Details Tab is used to input steam injection details. Steady State/Transient Conditions Specify whether the condition is transient or steady-state. The condition selected determines the calculation used for temperature. When Transient Conditions is selected, you can also specify initial conditions for the operation. Depending on your selection, the program uses the values from the Undisturbed Temperatures dialog and from the operation listed. Prior Operations The prior operation to which the current operation will be linked. The current operation will obtain its initial temperature conditions from the prior operation selected here. This is a desirable feature when modeling production operations that are sequential in order so that the well temperature history can be accurately tracked. Model Permeable Layers When the operation type is either reactive gel treatment or some injections, permeable layers can also be included in the analysis. In order to use this option you must have a layer defined in the Lithology Spreadsheet with 'Yes' selected in the 'Permeable Layer?' column. To choose 'Yes', the layer must have a permeability greater than zero defined in the Formation Properties Spreadsheet.
This check box is disabled when Air, or the Standard Hydrocarbon, VLE Hydrocarbon, or File-Defined Hydrocarbon is selected as the injection fluid. The check box is marked as the default when Reactive Gel Treatment is the operation type, or any of the other injection operations are selected. Copy Op Use this button to copy a previously defined production operation as a new operation with the same input parameters. The new operation can be renamed and the input values modified to develop a unique production operation from a previously defined production operation. To use the feature, highlight (select) the operation to copy and then click Copy Op to create a copy at the end of the Name list.
After making your selections, click Details to access the Operation Details dialog so values for the specific operation can be completed.
Loads Menu Click a command for a description.
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Design Parameters Tool Passage
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Initial Conditions
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Loads (Casing)
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Loads (Tube)
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Displacement Study
Design Parameters Dialog (Tools > Select Product > Casing or Tub, then Loads > Design Parameters) This dialog uses two tabs to specify pipe body design factors, analysis options to be included in the analysis.
optional design factors for connections, and
Click a name for information about that tab.
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Design Factors Analysis Options
Design Factors Tab (Tools > Select Product > Casing or Tube, then Loads > Design Parameters > Design Factors tab.) Use the Design Factors tab to define design factors that specify the minimum acceptable safety factors for the pipe body and connections for all loads. The program uses the design factors you specify for pipes and connections to identify design limits. For example, the program includes the design factors you specify in safety factor plots. The program also includes warning
messages in safety factor summary views and in the Tube, Casing, and MultiString Results Summary printed reports when a calculated safety factor is less than a design factor. Connection design factors can also be specified for values such as tension, compression, and burst/leak. The default for tension and compression is equal to the pipe axial design factor. The default for burst/leak is equal to the pipe burst design factor. Calculated axial and burst safety factors are the lesser of pipe body or connection limits. Since connection strength ratings are usually based on failure, and pipe body calculations are based on yield, a different design factor can be applied to the connections for tension and/or compression. You can define your own design parameters using the fields provided.
Fields and Controls Pipe Body Use this group box to specify the minimum acceptable safety factors for the pipe body. Below are the Pipe Body default values. Field Name Triaxial Burst Collapse Axial Tension Axial Compression
Default Value 1.250 1.100 1.000 1.300 1.300
Connection Use this group box to specify optional design factors for connections. Below are the Connection default values. Field Name
Default Value
Burst/Leak
1.100
Tension
1.300
Compression
1.300
Tool Passage Dialog (Tools > Select Product > Tube, then Loads > Tool Passage) Use the Tool Passage dialog to specify the outer diameters and lengths of the tools in order to verify that the tools can pass through the curved tubing in a dogleg or buckled section. Tools of a specified OD and length can be entered to analyze whether they will pass through the tubing under load conditions determined from initial conditions and subsequent load cases. Tubing bending occurs due to buckling and/or doglegs you specified when you defined the well. The maximum tool length is calculated for a given OD that can pass freely through the tubing at the depth of greatest tubing curvature. If the specified length is greater than the calculated length that can pass freely, the force required to push or pull the tool through the tubing is calculated. In order to calculate tool passage
Tube must be in use
At least one tubing string must be defined in the Casing and Tubing Configuration spreadsheet
The program assumes the following when calculating tool passage:
A 0.3 coefficient of friction between the tool and the tubing ID
Tool bending stiffness is that of a solid steel cylinder
Fields and Controls Tool-OD Specify the nominal outer diameter of the tool. OD must be < the drift diameter for the current string as defined in the Pipe Inventory spreadsheet. Diameter is the Unit System parameter used. Tool-Length Specify the length of the tool. This length must be ≤ the length of the current string. Depth is the Unit System parameter.
Initial Conditions Dialog (Tools > Select Product > Casing or Tube, then Loads > Initial Conditions) Use the Initial Conditions dialog to specify the initial conditions for the load by defining casing/tubing and annulus profiles. Standard initial conditions for Tube are undisturbed temperatures and densities from the Undisturbed Temperatures dialog and Annulus Contents spreadsheet, respectively. Standard initial conditions for Casing are undisturbed temperatures and densities generated from the primary cementing and landing data. Detailed initial conditions can be entered, which include values at different depths for temperatures, pressures, and densities. Initial conditions refer to the temperatures and pressures at the point in time when the casing/tubing is landed. Initial condition values should be entered, at a minimum, at the string’s top and base. Depth values refer to measured depths (MD). Density values only need to be entered for depths at the base of the fluid interface. With only one fluid in the hole, this depth is at the base of the pipe. Temperature values are assumed linear between the entered depths and should be entered at the string’s top and base. You must be using Casing to define casing profiles and Tube for tubing profiles. Three tabs are used to specify these conditions.
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String Annulus
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Comments
Loads Dialog (Casing) (Tools > Select Product > Casing, then Loads > Loads) Use the Loads dialog to define the load type you want to analyze for the current casing, scab liner, liner, or tieback string using a suitable selected external pressure profile. You can analyze any of these string sizes and types defined in the Casing and Tubing Configuration spreadsheet. If you previously selected a valid casing, liner, or tieback string, it will appear in the Loads dialog. A string can be selected using Wellbore > Current String, or by choosing a string from the drop-down list box in the Casing and Tubing Configuration spreadsheet. For a listing of the string selection methods available, see Selecting a String.
If a valid string is not selected, the Choose Error Handling Action dialog appears with all available strings. Highlight a string and click OK. The Loads dialog appears with your selected string posted above the Type dropdown list box. To use this dialog, first select a load from the Load Type drop-down list box, and then, select an appropriate external pressure profile from its drop-down list box. Keep in mind that all external pressure profiles not are available for all strings. Only those profiles appropriate are available. Note: Custom Load, Green Cement, and Overpull do not have external pressure profiles.
Click Copy Load to copy a previously defined casing load as a new casing load with the same input parameters. The new casing load can be renamed and the input values modified to develop a unique casing load from a previously defined casing load. To use this feature, highlight (select) the casing load to copy and then click Copy Load to create a copy at the end of the Name list.
After you select your load type and profile, click Details to access the Load Details dialog so you can define load type and external pressure profile details.
Loads Dialog (Tube) (Tools > Select Product > Tube, then Loads > Loads) Use the Loads dialog to define the tubing load type you want to analyze for the tubing string. The Loads dialog appears with your selected string posted above the Type drop-down list box. To use this dialog, select a tubing load from the Load Type drop-down list box. All loads supported by WELLCAT are available. When specifying Transient Injection as the load type, the Duration field is enabled for you to specify the transient flow period. Enter a numeric value for the duration, and then specify the time units, such as minutes or days. Time is the Unit System parameter.
Use this button to copy a previously defined tubing load as a new tubing load with the same input parameters. The new tubing load can be renamed and the input values modified to develop a unique tubing load from a previously defined tubing load. To use this feature, highlight (select) the tubing load to copy and then click Copy Load to create a copy at the end of the Name list.
After you select your load type and profile, click Details to access the Load Details dialog so you can define the load type. PROD simulations do not honor packer discontinuities, which is a standard behavior. Tube load, either prod link or standard (hybrids type), will honor the occurrence of packers, inducing a pressure discontinuity if applicable, depending on the nature of the packer defined (hanger, PBR, ASV).
Analysis Menu The Analysis menu has commands for accessing dialogs you use to input data for evaluating the effects of loading conditions on all load-bearing strings in the well system. In order for a MultiString analysis to be correctly conducted, Drill and Prod operations must first be defined to establish Casing and Tube initial and final temperature conditions for each string. This is vitally important for the MultiString analysis to be meaningful and correct. After all requirements described above are completed, use the Analysis menu commands to input data necessary for MultiString analysis. All commands are under two submenus.
Click an item for a submenu description. • •
Annular Fluid Expansion Wellhead Movement
Enter all the required input data in the dialogs under the Annular Fluid Expansion submenu if you only intend to model annular fluid expansion (Results > Summaries > MultiString AFE). If however, you want to model only the wellhead movement (Results > Summaries > MultiString Wellhead Movement), or both wellhead movement and annular fluid expansion, you must use the Wellhead Movement submenu options and provide input data. You must calculate the data using the Calculate dialog (Results > Calculate) before results will be available for viewing.
Results Menu Click the product you are using to display the correct Results menu. • Casing • Drill • MultiString • Prod • Tube
Results Menu (Drill) Click a command for a description. • Calculate • Current Operation • Deviation • Undisturbed Temperature Plot • Single Operation • Multiple Operations • Summaries • Reports Dialog • Reports
Results Menu (Prod) Click a command for a description. • Calculate • Current Operation • Deviation • Undisturbed Temperature Plot • Single Operation • Multiple Operations • Summaries • Reports Dialog • Reports
Results Menu (Casing) Click a command for a description. • Calculate • Current Load • Deviation • Dogleg Profile Plot • Undisturbed Temperature Plot • Single Load • Multiple Loads • Summaries • Reports Dialog • Reports
Summaries Click the product you are using to display the correct Summaries submenu. • Casing • Drill • MultiString • Prod • Tube
Summaries (Casing) (Tools > Select Product > Casing, then Results > Summaries) This submenu allows you to display summary results for a single load case that you specify when using Casing. The following profiles are available:
• Movement • Safety Factor • Casing Load • Ratings
Summaries (Drill) (Tools > Select Product > Drill, then Results > Summaries) This submenu allows you to display summary results for a single operation that you specify when using Drill. The following profiles are available:
• Operation • Wellbore Temperature
• Flow
Summaries (Prod) (Tools > Select Product > Prod, then Results > Summaries) This submenu allows you to display summary results for a single operation that you specify when using Prod. The following profiles are available:
• Operation • Wellbore Temperature • Flow
Summaries (Tube) (Tools > Select Product > Tube, then Results > Summaries) This submenu allows you to display summary results for a single load case that you specify. The following profiles are available:
• Movement • Safety Factor • Tubing Load • Tool Passage • Packer Load • Ratings
Tools Menu Click a command for a description.
Select Product
Next in Wizard
Previous in Wizard
Toolbars
Tabs
Options
Unit Systems
Convert Depth
Ratings
Library
Error Logging System
Select Product (Tools > Select Product) This command displays a submenu listing the Landmark products that can be used with the active well file.
Drill
Prod
Casing
Tube
MultiString
If a product is not installed on your system, the product command displays in light gray indicating that it is disabled. When you save the active well file, the program also saves your current product selection. For example, if you last used Prod with file A, the program starts Prod the next time file A is selected. Note As a shortcut, you can also access these products by clicking their buttons on the Product toolbar.
TUTORIAL AND EXAMPLES
Soil Interaction Workflow The following steps indicate a typical workflow you might use to perform a wellhead movement analysis including soil interaction.
Using the Inventory Menu 1. Define cement properties using the Cement Properties Spreadsheet . 2. Define fluid properties using the Fluids Inventory Dialog . 3. Define formation and soil properties using the Formation Properties Spreadsheet and the Soil Properties Spreadsheet . 4. Define other inventory information that pertains to your particular analysis using the Inventories Menu .
Using the Prod Module 5. Activate the Prod module using Tools > Select Product or by clicking the 6. Define the well using the General Dialog and the Offshore Dialog .
toolbar button.
7. Define the wellpath using the Wellpath Editor Spreadsheet . 8. Define the undisturbed temperature using the Undisturbed Temperature Dialog . 9. Define the lithology using the Lithology Spreadsheet . 10. Define the soil displacement using the Soil Displacement Spreadsheet . 11. Define the casing and tubing configuration using the Casing and Tubing Configuration Spreadsheet . 12. Define the annulus contents using the Annulus Contents Spreadsheet . 13. Define production operations using the Operations Dialog . 14. Perform the calculations using Results > Calculate.
Using the MultiString Module 15. Activate the MultiString module using Tools > Select Product or by clicking the toolbar button. 16. Define the outermost string using the Casing and Tubing Configuration Spreadsheet .
17. Define wellhead static loads using the Static Load Definition dialog . 18. Define wellhead movement load history using the Load History Definition dialog . If there are no loads, use the worst case production operation. Landing loads are defined automatically. 19. Calculate results using Results > Calculate. Be sure to select the Calculate Wellhead Movement and Soil-Interaction Model options on the Calculate Multax dialog . Note: AFE analysis can be included in the Wellhead Movement – Soil Interaction Analysis. To include AFE analysis, specify the AFE analysis details and be sure to check the Calculate AFE box on the Calculate Multax dialog .
20. Analyze results using: MultiString Wellhead Movement Displacement Summary Wellhead Movement Load Summary Wellhead Movement Axial Loads (Single Load) Wellhead Movement Axial Loads (Multiple Loads) String Displacement Plot
TLP Description The TLP/Hybrid well type is any well completed, subsea or otherwise, with casing strings hung off on a mudline hanger or at surface. If the casing strings are hung off at the mudline, they may or may not be tied back to the surface by means of a surface tieback. The sections from the surface to the mudline and from the mudline to the shoe could be run at the same time (as a continuous string) or separately. Three-section string configuration (e.g., liner to double tieback or liner double scab liner) and Subsea Wellhead Hanger Seal condition are coupled with MultiString AFE analysis as new functionality associated with the new TLP/Hybrid configuration. Previously in WELLCAT, only onshore, subsea, and platform configurations were possible; TLP/Hybrid -type configurations could only be approximated using double liners and scab liners. For this release, WELLCAT has been enhanced to handle TLP/Hybrid as the Well Type. The following documents the changes to WellCat as a result of adding the TLP capabilities. If you prefer to review the changes by watching a video, you can access a video at the following file location. Otherwise, you can review or print the contents of this help topic. \Server\TLP_Overview.exe General Dialog The Wellbore > General dialog now includes TLP/Hybrid as a Location option. A TLP/Hybrid description is displayed on the dialog when TLP/Hybrid is selected.
The TLP Tutorial basically refers to casing and tubing design of a well completed subsea with casing string hanged off on a mudline hanger or at the surface
ELEVATION: The interval from rotary kelly bushing (RKB) to the mean sea level (MSL), The interval from RKB to mudline is 3000ft, TOC represents top of cement, and Base represents bottom of cement being the depth of casing shoe for a specific casing
SOME OTHER PLOTTED PARAMETERS
Didn’t want to attend the Multistring module due to its complexity, so continuing from the Drill module
END FOR ME
Steam injection is an increasingly common method of extracting heavy oil. It is considered an enhanced oil recovery (EOR) method and is the main type of thermal stimulation of oil reservoirs. There are several different forms of the technology, with the two main ones being Cyclic Steam Stimulation and Steam Flooding. Both are most commonly applied to oil reservoirs, which are relatively shallow and which contain crude oils which are very viscous at the temperature of the native underground formation. Steam injection is widely used in the San Joaquin Valley of California (USA), the Lake Maracaibo area of Venezuela, and the oil sands of northern Alberta (Canada).
[edit] Cyclic Steam Stimulation This method, also known as the Huff and Puff method, consists of 3 stages: injection, soaking, and production. Steam is first injected into a well for a certain amount of time to heat the oil in the surrounding reservoir to a temperature at which it flows. After it is decided enough steam has been injected, the steam is usually left to "soak" for some time after (typically not more than a few days). Then oil is produced out of the same well, at first by natural flow (since the steam injection will have increased the reservoir pressure) and then by artificial lift. Production will decrease as the oil cools down, and once production reaches an economically determined level the steps are repeated again. The process can be quite effective, especially in the first few cycles. However, it is typically only able to recover approximately 20% of the Original Oil in Place (OOIP), compared to steam flooding, which has been reported to recover over 50% of OOIP. It is quite common for wells to be produced in the cyclic steam manner for a few cycles before being put on a steam flooding regime with other wells. The mechanism was accidentally discovered by Shell while it was doing a steam flood in Venezuela and one of its steam injectors blew out and ended up producing oil at much higher rates than a conventional production well in a similar environment.
[edit] Steam Flooding In a steam flood, sometimes known as a steam drive, some wells are used as steam injection wells and other wells are used for oil production. Two mechanisms are at work to improve the amount of oil recovered. The first is to heat the oil to higher temperatures and to thereby decrease its viscosity so that it more easily flows through the formation toward the producing wells. A second mechanism is the physical displacement employing in a manner similar to water flooding, in which oil is meant to be pushed to the production wells. While more steam is needed for this method than for the cyclic method, it is typically more effective at recovering a larger portion of the oil. A form of steam flooding that has become popular in the Alberta oil sands is steam assisted gravity drainage (SAGD), in which two horizontal wells are drilled, one a few meters above the other, and steam is injected into the upper one. The intent is to reduce the viscosity of the bitumen to the point where gravity will pull it down into the producing well. In 2011 Laricina Energy combined solvent injection with steam injection in a process called solvent cyclic steam-assisted gravity drainage (SC-SAGD).[1] Laricina claims that combining solvents with steam reduces the overall steam oil ratio for recovery by 30%.
Steam Operation With Sheared Expansion Joint Workflow This two part workflow is comprised a steam injection operation analysis followed by an expansion joint analysis. Included in this help topic is a general discussion of the workflow, as well as specific workflow steps. Click on one of the following links to go directly to the workflow steps you are interested in. Steam Operation Workflow Steps Sheared Expansion Joint Analysis Workflow Steps General Workflow Discussion This workflow analyzes a steam operation with an expansion joint packer. Modeling this type of operation and well configuration requires the usage of multiple WellCat modules. Typically this type of operation is performed on shallow to medium depth deviated wells. This steam operation workflow involves injection through the tubing, through the annulus, and through the tubing and annulus simultaneously. The steam fluid analyzed in the steam operation can be defined as Dry Steam (superheated), or Wet Steam (saturated). The steam fluid properties required to perform the analysis are
defined at standard surface conditions. The required properties depend on the type of steam, as follows: • •
Wet Steam (saturated) - Quality, and inlet temperature Dry Steam (superheated) - Wellhead pressure, inlet temperature
The injection rate conditions can be specified as mass rate, or volumetric rate at surface conditions. If there is any concern about the thermal impact of prior events on the steam injection operation results (Steam Quality and Total Heat Loss), this can easily be taken into account by defining a sequence of events in which the end result of the previous event is the initial condition for the following event. The Steam operation discussed in this workflow is performed using a completion string with a mechanically set integral packer, and an expansion joint. The expansion joint is run as an integral part of the tubing. Typically the expansion joint assembly is run with the PBR (polished bore receptacle) down, and the seal stem up. By allowing the associated packer and expansion joint reference depths to be specified separately, it is possible to represent the expansion joint assembly disconnected from the production packer assembly with several hundred feet between the two. When defining the expansion joint initial conditions, the following three issues need to be considered: • •
PBR shear-out mechanism activation setting/mode Packer setting procedure
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Expansion assembly space out
This workflow and the input data are for example purposes only. Steam Operation Workflow Steps 1. Perform the steps outlined in General Well Setup for Steam Operation With Sheared
Expansion Joint Workflow. 2. Access the Prod module using Tools > Select Product > Prod. 3. Define a steam tubing injection operation. a. Using Operations > Operations, select the Configuration as Production Tubing. Define the tubing flow path, the operation type, and the fluid. This example uses Dry Steam, however Wet Steam is another option. Select Transient Conditions and Undisturbed as the Prior Operation.
StressCheck is a unique, graphically based, interactive program that allows you to quickly and accurately design casing based on load cases and design factors that you specified on easy-to-use entry forms. StressCheck The design engineer's job is not completed after creating a casing design. • •
More information can subsequently be made available that changes the design premises. Operational circumstances may dictate a change in design.
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Good engineering practice includes performing parametric studies on an existing design.
One of the outstanding features of StressCheck is that, once a design is created, it is very easy to quickly change an input parameter and see the consequences it has on the design. StressCheck Functions In addition to being a design tool, StressCheck can also perform the following functions: • •
Be an analysis tool to check an existing design. Be a monitoring tool during drilling operations to determine whether well circumstances require a design modification.
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Be a post-analysis tool to ensure an existing well installation meets all production design criteria.
Performing Parametric Studies
Some parametric or sensitivity studies that can easily be performed in StressCheck include: • •
Change installation parameters on the Cementing and Landing tab, such as whether the float failed or the pickup force used. Change well geometry on the Casing Scheme spreadsheet including shoe and TOC depths.
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Change load case assumptions such as mud densities used, the volume and intensity of kicks, and whether a cement job results in zonal isolation.
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Change design criteria, such as the maximum number of sections in a minimum cost design.
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Restrict or expand the existing pipe inventory.
