Reservoir Operating Envelope Recommendations as Input into Limit Diagrams for HP/HT, Complex, Sour Carbonate Reservoirs

Abstract Reservoir offtake limits can be imposed for fields or certain areas per field or certain reservoirs as deemed necessary for safe and optimized production/operation of a hydrocarbon bearing reservoir. Key reasons to limit the production offtake for a certain field can include: Safeguarding long-term URMinimizing water production, thus avoiding artificial lift or any integrity (corrosion) issuesMaximizing key hydrocarbon phase productionWell, Reservoir and Facility Management (WRFM) purposes Reservoir offtake limits were established for HP/HT deep Middle Marrat (MM) reservoirs (gas condensate and volatile oil reservoirs) using the dynamic simulation models. These reservoir offtake limits are the average rates that can be produced without negatively impacting the long-term value (i.e., UR) or short-term excessive water production. With all constraints removed from the dynamic simulators except flowing bottom hole pressure (FBHP) and/or drawdown (i.e., CIBHP – FBHP), these limits reflect the capability of the reservoirs with the current well stock independently of any restrictions in the tubing, choke or back pressures from the facilities. Thus, these reservoir offtake limits may not be realizable with the current facility/well/choke/flowline arrangement., i.e., for example compression, pumps or artificial lift may need to be installed to deliver these rates. These limits are proposed to maximize the long-term revenue value ($). Next step is to use these reservoir limit into the system limit diagram to determine asset production limit considering all production system (reservoir, facility, well, chokes, and flowline). Output from this work is a list of production rates and constrains including DD limits in order to safely produce the reservoirs. These analyses helped to support optimizing production from current producing wells in a safe and efficient way which enhance reservoir health and optimize operation envelop. This is a very important part to safely and optimally manage reservoir performance without impacting long term value through determine and reduce impact of any bottleneck in the production system.