2002 Spring ASME/API Gas-Lift Workshop Gas-Lift Surveillance In Search of Hidden Production and Efficiency By Dan Dees, AppSmiths Cleon Dunham, Oilfield Automation Consulting Burney Waring, Shell EP Technology February 5 & 6, 2002 2002 Spring Gas-Lift Workshop

Gas-Lift Surveillance In Search of Hidden Production and Efficiency Surveillance is a Process It is a process of planning and designing for optimum operations; then continually looking for, finding, and addressing opportunities to overcome inefficiencies, weaknesses, and faults in these operations so that improvements can be made and maintained. February 5 & 6, 2002 2002 Spring Gas-Lift Workshop

Gas-Lift Surveillance In Search of Hidden Production and Efficiency True gas-lift surveillance is a comprehensive process that empowers trained gas-lift staff to optimize the artificial lifting of oil wells with gas-lift. The difference between poor and optimized gas-lift systems and wells can be hundreds of barrels of oil, and therefore thousands of dollars of income per day. February 5 & 6, 2002 2002 Spring Gas-Lift Workshop

Gas-Lift Surveillance In Search of Hidden Production and Efficiency Goal of gas-lift surveillance --- keep the entire gas-lift system (wells, gathering system, treating system, compression system, distribution system, and injection system) operating optimally, all of the time. This can not be done by traditional means. It requires state-of-the-art tools and skilled personnel who are committed to and focused on the task. February 5 & 6, 2002 2002 Spring Gas-Lift Workshop

Gas-Lift Surveillance In Search of Hidden Production and Efficiency Caution This paper is intended to provide gas-lift operating companies with specific information on how to develop a comprehensive surveillance process to optimize their gas-lift operations. In some cases, we mention specific goods, products, and services when, in our opinion, they represent state-of-the-art, yet field proven solutions that can be applied today. If we fail to mention other products and services that are also effective, we apologize. February 5 & 6, 2002 2002 Spring Gas-Lift Workshop

Gas-Lift Surveillance In Search of Hidden Production and Efficiency Gas-lift surveillance is difficult but rewarding work. Typical (field proven) gains can be: 10% or more oil production, plus 10% or more savings in lift gas, plus Often reductions in CAPEX and other OPEX For example: Field with 100 wells capable of 600 BOPD per well Produces 55,000 BOPD or less (potential 60,000 BOPD) Potential gain is $100,000 per day ($35MM per year) or more February 5 & 6, 2002 2002 Spring Gas-Lift Workshop

Gas-Lift Surveillance In Search of Hidden Production and Efficiency Primary goals of gas-lift: Continuous gas-lift Inject as deep as possible Inject on a continuous, stable basis Inject at optimum rate Intermittent gas-lift Inject optimum volume of gas beneath a column of liquid Inject each cycle at the optimum time (frequency) February 5 & 6, 2002 2002 Spring Gas-Lift Workshop

Gas-Lift Surveillance In Search of Hidden Production and Efficiency Continuous gas-lift surveillance Most important goal --- depth of injection Role of surveillance system Assure mandrel spacing is correct, as well matures. Assure valves support unloading & then close as needed. Assure well works down and stays there. Second goal --- stability Detect any instability. Assist in analyzing and trouble shooting cause(s) of instability. February 5 & 6, 2002 2002 Spring Gas-Lift Workshop

Gas-Lift Surveillance In Search of Hidden Production and Efficiency Continuous gas-lift surveillance Third goal --- optimum rate Role of surveillance system Always "know" the optimum rate(s) for the well and its gas-lift equipment --- they may not be the same. If well changes (and it will), operation and/or equipment must also be changed to maintain optimum operation. Keep the well as close to optimum as possible, while keeping system in balance. Other goals Continuously check for leaks, blockages, failed valves, etc. February 5 & 6, 2002 2002 Spring Gas-Lift Workshop

Gas-Lift Surveillance In Search of Hidden Production and Efficiency Intermittent gas-lift surveillance First goal --- system stability Role of surveillance system Keep system stable, even in face of inherent intermittent instability. Second goal --- optimum injection volume and time Precisely measure and control injection volume and time. Adjust injection cycle (size and frequency) as needed. February 5 & 6, 2002 2002 Spring Gas-Lift Workshop

Gas-Lift Surveillance In Search of Hidden Production and Efficiency Intermittent gas-lift surveillance Third goal --- optimum liquid recovery per injection cycle Role of surveillance system Monitor, and if possible, measure each liquid slug. Provide information to assist in optimizing intermittent injection cycle volume and frequency to maximize daily oil recovery. Other goals Continuously check for leaks, blockages, failed valves, etc. February 5 & 6, 2002 2002 Spring Gas-Lift Workshop

Gas-Lift Surveillance In Search of Hidden Production and Efficiency Surveillance process --- what is needed? People --- the gas-lift team Gas-lift champion Gas-lift engineer(s) Gas-lift technician(s) or programmer(s) Well analyst(s) Well services Operators Others Whether these functions are performed by one or several people, by company or contract staff, they are all essential. February 5 & 6, 2002 2002 Spring Gas-Lift Workshop

Gas-Lift Surveillance In Search of Hidden Production and Efficiency Surveillance process --- what is needed? Processes Have an effective work process and work as a team. Meet frequently --- in person or "electronically." Provide an adequate training process. Classroom Training models --- both physical and computer-based One-on-one mentoring Train the trainer On-line and web-based training Conferences and workshops There must be a complete, continuous training process for people to acquire and maintain needed skills. February 5 & 6, 2002 2002 Spring Gas-Lift Workshop

Gas-Lift Surveillance In Search of Hidden Production and Efficiency Surveillance process --- what is needed? Information Reservoir information --- PVT data, pressure, IPR Well information --- physical well design System information Economics --- optimize income, not production Pressure surveys Pressure build-up Static pressure Flowing pressure survey to evaluate current performance Flowing pressure survey to determine IPR February 5 & 6, 2002 2002 Spring Gas-Lift Workshop

Gas-Lift Surveillance In Search of Hidden Production and Efficiency Surveillance process --- what is needed? Information (Continued) Well tests Accurate well tests Or if possible, continuous well production rate Real-time information Need to have Distribution system gas pressure and availability Well injection rate and injection pressure Well production pressure Nice to have Manifold pressure Downhole flowing bottom-hole pressure February 5 & 6, 2002 2002 Spring Gas-Lift Workshop

Gas-Lift Surveillance In Search of Hidden Production and Efficiency Surveillance process --- what is needed? Tools Gas-lift design tools Use modern, computer-based design tools. But, know what they are doing. Quality assurance Check every valve before it is run and after it is pulled. Monitoring system Gather gas-lift information once per minute. Process and summarize the data so people can be presented with actionable information. Present it to people when and where they need it. February 5 & 6, 2002 2002 Spring Gas-Lift Workshop

Gas-Lift Surveillance In Search of Hidden Production and Efficiency Surveillance process --- what is needed? Tools (Continued) Control system Keep system in balance, under all conditions. Keep wells as close as possible to optimum at all times. Keep wells stable during well tests. Maintain required unloading rates. Keep injection cycles as designed. Analysis Analyze the cause of each problem so it can be fixed correctly this time and prevented from happening again. February 5 & 6, 2002 2002 Spring Gas-Lift Workshop

Gas-Lift Surveillance In Search of Hidden Production and Efficiency Surveillance process --- what is available? Good news Excellent goods, tools, and services are available to help optimize each company's gas-lift operations. See www.wellanalysis.com and www.alrdc.com People It is essential to have some "company" people who are focused on gas-lift --- this is "core" business. And, there are several service companies that can provide excellent assistance --- either short or long term. February 5 & 6, 2002 2002 Spring Gas-Lift Workshop

Gas-Lift Surveillance In Search of Hidden Production and Efficiency Surveillance process --- what is available? Processes Work process Each company must develop its own work process with which it is comfortable. Classroom training Several good courses are available --- check with Shell, Weatherford, EPS, and others. Training models Free computer-based training models are available --- check with Shell, Weatherford, Schlumberger, and others. A physical model can be developed --- check with the authors. February 5 & 6, 2002 2002 Spring Gas-Lift Workshop

Gas-Lift Surveillance In Search of Hidden Production and Efficiency Surveillance process --- what is available? Processes (Continued) One-on-one training, and "train the trainer" Each company should have at least one person --- company or contract --- who can train local staff on a one-on-one or one-on-few basis. On-line, web-based training Excellent tools are becoming available to provide highly leveraged training –-- when and where it is needed. Check with Shell and others. February 5 & 6, 2002 2002 Spring Gas-Lift Workshop

Gas-Lift Surveillance In Search of Hidden Production and Efficiency Surveillance process --- what is available? Information Each company must acquire the necessary information on its own reservoirs, systems, and wells. Several important references are listed in the paper. Especially refer to API RP 11V8 --- Recommended Practice for Gas-Lift System Design and Performance Prediction. This is to be released in the near future. It can be seen on the www.wellanalysis.com web site. February 5 & 6, 2002 2002 Spring Gas-Lift Workshop

Gas-Lift Surveillance In Search of Hidden Production and Efficiency Surveillance process --- what is available? Tools Design We recommend the Shell WinGLUE program. There are other excellent design programs available from EPS, Baker Jardine, Petroleum Experts, and others. WinGLUE uses gas-lift valve performance models developed by the Valve Performance Clearinghouse. It uses an SQL database. All information, once entered, is kept on line for future use. It uses "wizards" to assist in easily running the design process. It supports designing with choked unloading valves, if desired. February 5 & 6, 2002 2002 Spring Gas-Lift Workshop

Gas-Lift Surveillance In Search of Hidden Production and Efficiency Surveillance process --- what is available? Tools (Continued) Quality assurance We recommend fully testing every gas-lift valve, both before it is run and after it is pulled. We recommend a new tool called the Gas-Lift Valve, Automatic Validation Tester. Each valve can be fully tested in about five minutes. Any faulty valve can be rejected before it is run. Monitoring Excellent real-time SCADA (production automation) systems are available from Shell and eProduction Solutions. Others are also available. February 5 & 6, 2002 2002 Spring Gas-Lift Workshop

Gas-Lift Surveillance In Search of Hidden Production and Efficiency Surveillance process --- what is available? Tools (Continued) Control These same systems can also provide the needed gas-lift system and well controls. We have first-hand experience with the Shell system for controlling both large and small, complex gas-lift systems that contain both continuous and intermittent wells. Analysis The Shell WinGLUE program supports a full suite of tools for analyzing the performance of gas-lift wells and helping to determine the causes of problems with these wells. There are other effective analysis tools available. February 5 & 6, 2002 2002 Spring Gas-Lift Workshop

Gas-Lift Surveillance In Search of Hidden Production and Efficiency Conclusion Comprehensive surveillance is essential It is highly profitable It is feasible and economic for any size company It requires dedicated, motivated, highly trained staff And it requires Effective work processes Excellent, on-going training Good, current information Excellent tools and the skills to use them February 5 & 6, 2002 2002 Spring Gas-Lift Workshop