孔洞型碳酸盐岩油藏不同开发方式物理模拟研究

Physical simulation for different development of vuggy carbonate reservoir

黄兴¹ 李天太² 杨沾宏³ 胡伟¹ 盖少华¹ 吕晓伟⁴

中国石油大学（北京）石油工程学院，北京102249 西安石油大学石油工程学院，陕西 西安 710065 中国石油长庆油田公司第六采油厂，陕西 西安 710200 中国石油华北油田公司勘探开发研究院，河北 任丘 062552

College of Petroleum Engineering, China University of Petroleum, Beijing 102249, China College of Petroleum Engineering, Xi′an Shiyou University, Xi′an 710065, China No.6 Oil Production Plant, Changqing Oilfield Company, PetroChina, Xi′an 710200, China Research Institute of Exploration and Development, Huabei Oilfield Company, PetroChina, Renqiu 062552, China

对于孔洞型碳酸盐岩储层，由于其特殊的孔洞结构特征，一般情况下很难使用其真实岩心开展长岩心驱替实验。在不影响原有岩心孔渗结构的基础上，对岩心表面凹陷处进行特殊填补处理，以达到长岩心实验要求。文中在油藏实际条件下，开展长岩心衰竭开采实验，水驱、气驱开发实验和气水交替驱实验，统计分析不同开发方式下各阶段的驱油效率，对比评价不同开发方式的开发效果。结果表明：衰竭开采最终采收率高达30.94%；水驱开发中，适当延迟转注时间能够充分发挥弹性驱油和溶解气驱油作用，提高最终采收率，并确定最佳转注压力为80%泡点压力；气驱开发中，气体突破速度快，突破后产油量急剧下降，采收率较低；气水交替驱能有效降低含水率，提升高含水期原油采收率，在高压高含水阶段转气水交替的开发效果更为显著。该实验为合理开发孔洞型碳酸盐岩油藏提供了基础数据和技术支撑。

Because of its special vuggy structure characteristics, it is difficult to carry out the long core displacement experiment by real vuggy carbonate core. Without affecting the original core porosity and permeability, the core surface depression is needed to be filled up to meet the requirements of long core test. In the simulation of the actual reservoir conditions, the depletion drive, water flooding, gas flooding and water alternate gas flooding tests were carried out. Oil displacement efficiency of each stage under different development mode is analyzed. The results show that the ultimate recovery of depletion drive is 30.94%; during water flooding, time postponement of water injection can give full play to the effect of elastic drive and dissolved gas drive and improve the ultimate recovery; the best injection pressure is 80% of the bubble point pressure; during gas flooding, gas breakthrough speed is fast, oil production declined sharply after breakthrough, the ultimate recovery is low; water alternate gas injection can effectively reduce the water cut and improve the recovery in high water cut stage; the development can be more significant when the conversion is at the stage of high water cut and high pressure. The experiment provides data and technical support for the rational development of vuggy carbonate reservoirs.

10.6056/dkyqt201601018