联合DWS和DWL技术开发气顶底水油藏的新方法

摘要

Gas cap oil reservoir with bottom water is one of the reservoirs difficult to be developed. During the reservoir develop⁃ment process, it is easy to hit gas coning and water coning which reduce the critical oil production. Therefore, based on DWS and DWL technology proposed by predecessors, and according to the fluid distribution, a new recovery method was proposed that is to shoot in 4 different parts in reservoir, separately install a packer in oil-gas interface and oil-water interface, and combine DWS with DWL. Gas is produced from the gas layer perforation through tubing casing annulus, crude oil is produced from oil perforating through tubing, and bottom water is circulated through two submersible pumps in the wellbore and formation. Based on the pressure balance principle of oil-gas interface and oil-water interface, reasonable formulas of daily gas production, daily oil production and water injection/drainage rate were established. The calculation of example showed that the results of the new method enhanced the critical production(1.52 times of the original method). This method provides new theory reference in reasonably developing the res⁃ervoir with gas cap and bottom water.%气顶底水油藏是一种较难开发的油藏。针对油藏开发过程中，容易导致气体和底水锥进，降低油井临界产量，以前人提出的双层完井排液（DWS）和井下底水循环（DWL）技术为基础，根据气顶底水油藏中流体分布的特征，提出在储层中4个不同部位分别射孔，油气界面和油水界面分别安装1个封隔器，联合DWS和DWL技术进行开采的新方法。气体由气层射孔段通过油套环形空间采出，原油由油层射孔段通过油管采出，底水通过水层两个潜水泵在井筒和地层中形成循环。根据油气界面和油水界面压力平衡的原则，建立了合理的日采气，日采油和注排水速度计算公式。实例计算表明：新方法提高了油井临界产量，大约为原方法的1.52倍。该方法为气顶底水油藏的合理开发提供了新的理论参考。