Introduction :
We need to produce as much as we can, but we just don’t want to upgrade our technology for today, we need to build the capability of the operation for tomorrow. The answer /solution to it is PRODUCTION OPTIMISATION.
Production Optimization is a method for analyzing the well which will allow the determination of the producing capacity for any combination of components. This may be used to determine the locations of excessive flow resistance or pressure drop in any part of the system. The effect of changing any component on the total well performance c an be easily determined. Production Optimization ensures that wells and facilities are operating at their peak performance at all times to maximize production. Optimization procedure:
Identify the components in the system Select one component to be optimized Select the node location that will best emphasize the effect of change. Develop expression for inflow and outflow. Calculate pressure drop versus rate for all components. Determine the effect of changing the characteristics of the selecting component. Repeat the procedure for every component. Optimize the production system.
There are number of key levers that will help to boost production. By optimizing production through more effective and efficient use of the existing asset and the resources already in place, there is less need to contemplate expensive technology acquisition and capital expenditure. It is the duty of the Production Engineers to provide crude oil the most optimum conduit and other parameters so as to bring it on the surface in the most economical and efficient way. The tubing size, type of completion should be chosen and designed in such a manner that it results in the production optimization and work effectively for longer well’s life. As the production is taken from the reservoir, as the result of pressure drawdown, reservoir pressure is reduced to such an extent that the oil ceases to flow. That is it loses its natural tendency to flow. At this point of time the oil is lifted from wellbore to surface by artificial means. There are various artificial lift methods like jet pump, SRP, gas lift etc. Depending on the suitability of the reservoir fluid properties, GOR, depth etc. particular artificial lift te chnique is selected for the well under consideration. PROSPER software is the tool in the hand of production engineers which help them to optimize the production by selecting the appropriate conduit and completion so as to minimize the pressure loses in the system. Not only this, it also helps to select when and on which artificial lift well has to be put on. Certain data of the well are collected and are fed into the software, which after performing certain calculations provide the user with graphs like IPR, VLP. The user needs to interpret inter pret the charts. Production optimization is the demand and necessity of every we ll in every field.
Literature Review:
An oil and gas reservoir contains highly compressible hydrocarbon fluids at an elevated temperature and pressure and fluid itself is under considerable energy of compression. The effective dissipation of energy is required for efficient production of fluids. Optimum utilization of this energy is an essential part of successful completion design and ultimately of field development economics. The productivity of well depends on pressure loses that generally occur at:
The reservoir (dependent upon the reservoir rock and fluid characteristics) The wellbore(The pressure drop generated by the perforations and other near wellbore completion equipment) The tubing string (caused by various sizes of tubing and through restrictions) The choke (cause a significant amount of pressure drop) The flowline (as fluid passes through them additional pressure losses occur) The separator
(1) frictional pressure loss, ie, loss associated with viscous drag. (2) hydrostatic head pressure loss due to the density of the fluid column in the production tubing. (3) kinetic energy losses due to expansion and contraction in the fluid flow area and the associated acceleration/deceleration of the fluid as it flows through various restrictions. PRES = DPRES + DPBHC + DPVL+ DPSURF + DPCHOKE + PSEP The pressure drop occuring across the reservoir, PRES is defined as the inflow performance relationship or IPR. The pressure drop which occurs in the tubing and wellbore PTBG is that which occurs in lifting the fluids from the reservoir to the surface and it is known as the vertical lift performance or VLP , or the tubing performance relationship or TPR. The optimum distribution of this energy between these various areas has a major bearing on the cost effectiveness of a well design and hence production costs. NODAL ANALYSIS or system analysis approach is a efficient method for analyzing a well , which will allow the determination of the producing capacity for any combination of components. The method may be used to determine the locations of excessive flow resistance or pressure drop in any part of the system. The effect of changing any component on t he total well performance can be e asily determined.
The procedure consists of selecting a division point or node in the well and dividing the system at this point. All the components upstream of the node comprise the inflow section, while the outflow section consists of all the components downstream of the node. The flow rate through the system can be determined once the following requirements are satisfied:
Flow into the node equals flow out of the node Only one pressure can exist at a node
PR - (Pressure loss upstream components) = P node Psep + (Pressure loss downstream components) = P node
The nodal analysis approach is flexible method that can be used to improve the performance of many well system. The procedure can be applied to both flowing and artificial lift wells, if the effect of the
artificial lift method can be expressed as a function of flowrate. The fluid production resulting from reservoir development will normally lead to a reduction in the reservoir pressure, increase in the fraction of water being produced together with a corresponding decrease in the produced gas fraction. All these factors reduce, or may even stop, the flow of fluids from the well. The remedy is to include within the well completion some form of artificial lift. Artificial lift adds energy to the well fluid which, when added to the available energy provided “for free” by the reservoir itself, allows the well to flow at a (hopefully economic) production rate. There are many factors affecting the selection of artificial lift. They are: Well and reservoir characteristics Field location Operational problems Economics Implementation Long term reservoir performance and facility constraints
Objective: The project will deal with an overall study of the factors influencing the performance of well along with the solutions that may be suggested to overcome that problem so that the optimization of the production of a well can be achieved. Use of prosper software will help in deciding the changes to be made in various parts and operations involved in production. Apart from that the type of artificial lift to be used for a particular well based on various parameters to be studied so that maximum production is achieved, will be included. The project aims at comprehensive, analytical and scientific study of the ways by which the production of a well can be optimized with the help of prosper software taking into consideration well data as case study.
Methodology:
PROSPER stands for advanced PROduction and Systems PERformance analysis software. Its powerful sensitivity calculations enable to optimize the existing design and the effect of future changes in the system parameters to be assessed. Each of the component of the producing well system can be modeled separately and then allow the user to verify each model subsystem by performance matching. Once the system model has been converted to real field data, it can be used for the modeling of the well under different conditions. PROSPER can help E&P companies to maximize their production earnings by providing the engineering means to analyze the performance of individual production or injection well. Each part of the system contributing to the overall performance is separately modeled. Fluid properties , inflow performance, pressure drop in tubing’s and in the surface gathering system are individually evaluated ,analyzed and calibrated against recorded performance data. Its sensitive calculations enable the engineers to model and optimize: tubing configuration, choke and surface flowline performance. It is also used to design and optimize the following artificial lift system: gas lifted, coiled tubing, ESP, hydraulic pump, jet pump and sucker rod pump equipped wells.
Prosper is a well performance, design and optimization program which is the part of the Integrated Production Modeling toolkit (IPM). It allows the unique matching features which tunes PVT, multiphase flow correlations (for the calculation of flow line and tubing pressure loss) and IPR (reservoir flow) to match the field data allowing a consistent we ll model to be built prior to be used for predictions. APPLICATIONS:
Used for designing and optimizing well completions including multilateral, multilayers and horizontal well. For designing and optimizing tubing and pipeline sizes. Design, diagnose and optimize gas lifted, hydraulic pumps and ESP wells. Generate lift curves for use in simulators. Calculate pressure losses in the wells, flow line and across chokes. Monitor well performance to rapidly identify wells requiring remedial actions.
The use of PROSPER software along with analytical reasoning for interpretation and selection of methods to be involved for production optimization and artificial lift will be covered in dissertation under the guidance of mentor.
References: Production Optimization Using Nodal Analysis 2nd Ed by H. Dale Beggs Well completion and servicing by Dennis Perrin www.princeton.edu/~wmassey/CAARMS8/Smczeal.pdf www.tseytlin-consulting.com/technologies/TPO-intro.htm
USE OF PROSPER SOFTWARE FOR PRODUCTION OPTIMIZATION AND ARTIFICIAL LIFT SELECTION
(SYNOPSIS)
submitted to:
PROF. A. S. CHANDEL
submitted by:
MEENU GUPTA ( R010208026) RAHUL RANAKOTI (R010208041)
