HP/HT well construction, well control issues and risk management How can a Research Institute contribute ?
Presented by Rolv Rommetveit, Rogaland Research
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Contents • • • • •
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Background R&D highlights within HPHT The HPHT Laboratory HPHT Integrated Studies How can an R&D Institute contribute ?
HPHT Drilling Research at RF-Rogaland Research Background • Prospects and Discoveries in Central Graben • Serious Well Control Problems during drilling of HPHT Wells • Need for understanding dynamic Pressures as well as Temperature effects in HPHT wells • HPHT Fields under development require solutions to production and reservoir related problems as well www.rf.no
HPHT Research Activities at RF-Rogaland Research From 1990 R&D within drilling and well technology started at RF • 1991 - 93 “Accurate Pressure Conditions in Deep, Hot Wells” JIP with 5 participants Development of an Advanced Model for Accurate Pressure and Temperature Calculations
• 1991 - 94
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Strategic Technology Programme from NFR “Well Technology in Deep, Hot Wells • Productions Problems related to HPHT reservoirs • Drilling related problems was further studied • Needs for Laboratories to study these phenomena was defined
HPHT Drilling Research at RF-Rogaland Research
1990 - 94: “Understanding Pressures and Temperatures during drilling under extreme conditions” (DEA-E-33 project)
Focus on: – – – –
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Field Measurements of P and T from 2 HPHT Wells Fluid Properties at HPHT (Rheology and Density) Verification of Pressure and Temperature models Development of recommendations for safer Tripping and Drilling
HPHT field data • Time based surface data • Time based downhole data – Near BOP – Top and bottom of BHA – 1000 m above BHA
• The data cover detailed tests in cased holes: – Gel tests – Surge and swab – Circulation sweeps –… www.rf.no
Laboratory experiments • 10 HPHT mud samples collected and analysed • Mud density at HPHT • Mud rheology at HPHT • Correlation based models developed
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Case 1: • 2.1 s.g. WBM • Vertical, 5000 m • Gel tests inside 9 5/8” casing Tests at bottom inside 7” liner
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Case 2: • • • •
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2.2 s.g. OBM Deviated, up to 27° 5100 m MD Tests inside 9 7/8” casing
Pressure (bar) 900
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800
400
700
600
15 20 Surge and swab
Circ. and cond. mud
Dress off cement plug
Pressure test
Reaming cement
1000
25 Time (hours) 30
Static period
Circulation sweeps, 200-1000 l/min
Gel tests w.o. rotation
Gel tests w. rotation
Bottom hole pressure, WBM
1200
1100
500
35
Pressure, gel test w.o. rot., WBM 860
Pressure (bar)
850 840 830 820 810 800 www.rf.no
18.3
18.4
18.5 18.6 Time (hours)
18.7
18.8
Pressure, swab/surge, WBM 1250 600 l/min
Pressure (bar)
1200
No circ.
1150 1100 1050 1000 950
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27.4
27.5
27.6 Time (hours)
27.7
27.8
Temperature, Transient p,T-model, OBM 165
Measured data Calculation
160
Temperature (C)
155 150 145 140 135 130 125 120 www.rf.no
35
40 Time (hours)
45
Operational recommendations developed for : • Pressure transmission • Drilling – Swab in critical zones • Recommended procedure for critical zones
– Surge in critical zones – Gelling
• Mud properties – Rheology and gel strength are very temperature dependent – HPHT laboratory measurements are recommended
• Use of thermo-hydraulic analysis www.rf.no
HPHT Research Activities at RF-Rogaland Research
ELF HPHT Drilling and Production Programme A Major Research Co-operation Based on Elgyn / Franklin needs
1992 - 1995 – Drilling Programme – Production Programme – HPHT Laboratory www.rf.no
Dynamic Barite Sag in Drilling Fluids Research funded by Elf and ENI / Norsk Agip
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Dynamic Barite Sag Dynamic barite sagging: When weight material in drilling fluid precipitates during circulation. • All drilling fluids show dynamic sagging during laminar shear flow. • Large differences in different drilling fluids with respect to rate of dynamic sagging. www.rf.no
Dynamic Barite Sag 2.50E-05 2.00E-05 1.50E-05 1.00E-05 5.00E-06 0.00E+00 Agip oil Agip water based: based:
Glydril:
Versa Vert 80/20:
Nova Plus 60/40:
CMC:
Xanthan:
Summary of sagging properties of drilling muds www.rf.no
Dynamic Barite Sag
• A method to measure dynamic sagging in drilling fluids has been developed. • A formalism to analyse the results have been established
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RF-ROGALAND RESEARCH HPHT Fluids Laboratory Testing of fluids at: Pressures up to 1500 bar Temperatures up to 200º C
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The RF rig area
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APPLICATION IN RESERVOIRS • • • • • •
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Phase behaviour of fluid mixtures Retrograde condensate evaluation Dew point determination Formation blocking Emulsion stability Foam properties
APPLICATION IN PRODUCTION • • • • • • •
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Scale formation studies and inhibition Wax and asphaltene formation Corrosion evaluation Chemical stability Emulsion stability Supercritical properties of gases Solvent properties in fluids
APPLICATIONS IN COMPLETION • • • • • • • • • www.rf.no
Well control Completion fluid characterization Gas / condensate solubility in completion fluids Thermal properties of packer fluids Salt solubility in brines Kill pill stability Fluid compatibilities Precipitation in the formation Emulsion stability
APPLICATIONS IN DRILLING • Well control • Kick control – Gas, condensate and oil influx in oil and water based mud
• ECD management • Drilling fluid characterization – Emulsion stability under HPHT conditions – Rheology stability under HPHT conditions – Static barite sagging under HPHT conditions – Thermophysical properties in fluids www.rf.no
The HPHT Mud Cell Principle •Piston cell with piston controlled by hydraulic pressure inside a heating cabinet •The cell volume (e.g. Position of the piston) is read by a linear encoder mounted on the side
Technical data •Position encoder for volume measurements •Robust tubing and valves to allow handling fluids weighted with solid agents •Well for temperature probe in the cell body •Computer interfaced data acquisition
Technical data •Pressure range: 0 to 1.370 bar
Applications •Thermal expansion of fluids
•Temperature limit: 200 C
•Compressibility of fluid
•Volume: 500 ml ( + 0.2% )
•Temperature and pressure effects of fluid components
•Material: Solid Hastelloy www.rf.no
HPHT-laboratory PVT-cell •Advanced PVT-apparatus
Principle •Similar to two big yolumetric pumps placed vertically within a large thermostat; with the pump cylinders utilized as cells •Pistons can compress sample or displace it back and forth to display interesting phenomena in windows
Technical data •1.500 bar maximum working pressure (20.000 psi) •-30 to 230o C temperature range •Volume:
700 cc (cell1), 100 cc (cell 2) Accuracy: γL-Level
•Material:
Solid Hastelloy Vespel (seals) Al2O3 (windows)
•Minimal dead volumes (valves integrated in cell bodies) •Flush-mounted pressure transducers www.rf.no
•Two interconnected variable volume chambers with motordriven pistons working directly into cells •Fully computer-interfaced control and data acquisition •Interchangable end-sections with a variety of sapphire windows for video-monitor or fiber-optic interface detection •Applications •All standard PVT with unprecedented accuracy •Direct dewpoint measurement •Visual (full-view colour video monitor) and quantitative studies of all phase transition phenomena (LV, L1,L2, Solid precipitation,...)
Conclusion • HPHT Fluids laboratory is highly relevant for drilling ,completion and reservoir related studies • Application in – Drilling and completion fluid characterization – Well control / kick control – Gas / condensate solubility – Baryte sag – Fluid stability – Fluid properties vs. Pressure and Temperature www.rf.no
HPHT Drilling Research: Kick Modelling and Control • A GENERAL TOOL FOR WELL CONTROL ENGINEERING AND ANALYSIS – A JIP for development of RF Kick Simulator
• Activities related to HPHT well control: – Extended PVT model – Special aspects of kicks in HPHT wells – Surface gas separation and flaring capabilities
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Design tool for work station (DEA-E-5)
Full scale kick tests in OBM (DEA-E-9)
Dissolved gas transport PVT-experiments in OBM Multilateral well control
Kick development in horizontal wells
Verification v.s. kick tests
Special kill procedures www.rf.no
HPHT Condensate kicks
Gas slip analysis Full scale kick tests for SHD (DEA-E-55)
KICK Deep water kick module
Blow-out kill model Shallow gas kicks
Full scale kick experiments in horizontal wells (DEA-E-50)
Kick with lost circulation
Multiple kicks from multiple zones
Kill of underground flow
General EOS-based PVT-module Gas rise in highly gelled mud Kick for slim hole drilling
Undetected connection kick Ile 1m3 kick, OBM, circ 1200 l/min
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Uniqueness of RF Kick • Can model gas, condensate and oil kicks (advanced PVT module) • Well suited for HPHT conditions • Verified for ultra-deep conditions • Can model complex scenarios (with lost circulstion etc.) • Realistic gas transport model enable degasser design evaluations • Less conservative (more realistic) than other models • Special wellsite version for kick tolerance evaluations on critical wells available • A necessary tool in the operator’s tool-kit for special wells and operations
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HPHT R&D Thermo-hydraulic modelling (PRESMOD) Thermo-hydraulic • Coupled pressure and temperature simulator • Radial and axial discretization • Dynamic simulations for studies of operational effects on pressure and temperature profiles • State of the art rheology and density models with possibilities to input of fluid lab. data www.rf.no
• JIP on HPHT Hydraulic Modeling since 1990 • Elf Transient Wellbore Temperature Model Belzeb
• Results from DEA-E-33 tests improved Model • Extensive verification • HPHT wells • Extended Reach Wells • Deep Water wells
Presmod Value and uniqueness • Presmod is a unique tool to optimize drilling procedures in wells with small margins • Presmod takes into full account the impact of operations-driven T and P changes on the ECDs • Casing running can be optimized www.rf.no
• •
Pressure loss 81/2” section CsFK mud Kristin well case
HPHT Research ; Critical pressure effects • Transient surge and swab pressure – Compressibility – Friction – Hole and casing elasticity
• Transient gel breaking pressure – Pump start-up and surge/swab when drilling
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Critical Pressure Effects Research activities
Computer software
1. Fluid characterization 2. Pressure transmission laboratory experiments Transient flow model with gel build-up and gel breaking
3. Flow start-up lab. experiments 4. Transient flow modeling 5. HPHT field tests www.rf.no
Gel breaking pressure near bottom 845
Pressure (bar)
840
Pressure at gauge A2 (DEA-E-33 WBM) Measured data No GEL With gelling
835 830 825 820 815 18.74 18.75 18.76 18.77 18.78 18.79 18.8 Time (hours)
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HTHP surge and swab calculation 1350 1300
Pressure at gauge A2 (DEA-E-33 WBM) Measured data Dynamic calculation Steady state
Pressure (bar)
1250 1200 1150 1100 1050 1000 27.38
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27.39
27.4 27.41 Time (hours)
27.42
27.43
KickRisk – project goals Develop a tool that: • • • • •
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Quantifies uncertainty to kick and blowout Reflects risk related to different design alternatives Highlights critical factors Assists identification of risk reducing measures Is a basis for cost-benefit studies of alternate measures
KickRisk Overview Norsk Agip
Norsk Agip
Norsk Agip
Oljedirektoratet
Norsk Hydro
Norsk Hydro
Statoil (upgrade)
Kick Analysis
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Oljedirektoratet
Loss of well control
Completed
Completed
In use
Qualification
Evaluation
Pilot study
Further development
Further development
Blowout flow module In progress
KickRisk Kvitebjørn Study • Objectives: – Quantify overall kick probabilities – Identify critical factors – Compare OBM and CsKF in terms of kick probability – Quantify fracturing probabilites – Sensitivity analysis on mudweight
• Methodology: – Data gathering via expert team Interviews – Analysis using KickRisk: Risk Analysis module www.rf.no
KickRisk Kvitebjørn Study • Analysis of fracturing probabilities for CsKF
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Example of application
KickRisk study on the Kristin field
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HPHT well studies in Rogaland Research Group •
Numerous HPHT wells drilled in Norway including 2/4-14 & 16 • Pre- and post analysis of well control
•
•
• Well control & transient hydraulics evaluations • Gas diffusion • Operational support
BP UK Marnock • Post analysis of well control problems
•
BP UK Devonick • theoretical evaluations • laboratory investigations • computer simulations and scenario developments with advanced modeling tools; drilling & completions • implementing learning's in procedures and operations • training • operational support
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BP Baku Shah Deniz wells
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Kvitebjørn ; Statoil • Computer simulations and scenario developments; advanced hydraulics • Kick Risk studies
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Kristin ; Statoil • theoretical evaluations; gas diffusion • computer simulations and scenario developments with advanced modeling tools; drilling & completions • implementing learning's in procedures and operations • training • Kick Risk studies
Topics for a Well Control Study
– Hydraulic calculations (ECD, swab pressures, temperature effects) – Kick Tolerances (swabbed, drilled and pressured fault kicks) – Undetected Kicks (in oil based Mud) – Gas Migration (free gas migration in brine) – Gas diffusion – Kill Methods – Surface Flow parameters/ Mud Gas Separator – Comparing kick behavior in brine vs. oil based Mud. www.rf.no
Value of advanced computer modeling • Advanced computer models can be very valuable in both the planning and training phase: – – – – –
Identify specific well control risks Input to Well Control Procedures (verify vs. improve) Contribute to optimization of well design Develop new procedures Realistic training
– Improve knowledge of HPHT wells – Improve kick tolerance calculations
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Future contribution from RF Group in order to unlock the HPHT Challenge • Well control and hydraulic studies using advanced , transient modelling tools • Planning, operation, and training • Development of procedures
• Operational support • QRA analysis – Kick probability using KickRisk – Operational risks
• Utilize HPHT Laboratory • Drilling, Completion, Production and reservoir studies
• Understand fully fluid properties ( barite-sag, stability, gas diffusion) www.rf.no
