北部湾盆地低渗透油藏产能分析方法  

A productivity analysis method of low permeability reservoirs in Beibu Gulf Basin

作　　者：张乔良 赵楠 隋波 王磊 杨朝强 岳绍飞 张风波 ZHANG Qiaoliang;ZHAO Nan;SUI Bo;WANG Lei;YANG Zhaoqiang;YUE Shaofei;ZHANG Fengbo(CNOOC China Limited,Zhanjiang Branch,Zhanjiang,Guangdong 524057,China;CNOOC China Limited,Hainan Branch,Haikou,Hainan 570311,China)

机构地区：[1]中海石油(中国)有限公司湛江分公司,广东湛江524057 [2]中海石油(中国)有限公司海南分公司,海南海口570311

出　　处：《中国海上油气》2025年第2期152-163,共12页China Offshore Oil and Gas

基　　金：中海石油(中国)有限公司重大科技专项“南海西部在生产油气田提高采收率技术研究(编号:CNOOC-KJ 135 ZDXM 38 ZJ 01 ZJ)”部分研究成果。

摘　　要：针对海上探井、评价井测试时间短导致低渗透油藏测试产能较实际生产差异明显的问题,基于质量守恒定律和考虑有效驱动因子的广义达西公式,建立了包含低速非达西渗流、储集层应力敏感、油藏压力保持水平等因素的油水两相渗流数学模型,推导出相应的产能评价与预测方程,利用南海西部北部湾盆地典型油藏的测试数据进行了产能分析。结果表明:低渗透油藏及时有效的能量补充能够获得较高的储集层渗流能力、驱油效率和油藏产能;研究区块生产压差在8.6~29.5 MPa时,储集层应力敏感和低速非达西渗流导致油藏产能减小分别为4.0%~12.8%、42.4%~84.4%,低速非达西渗流对产能的影响远远大于储集层应力敏感的影响,在不出砂和不影响油藏能量有效补充的前提下,采油井可通过放大生产压差获取较高的油藏产能;低渗透油藏测试产能与稳定产能的差别随着储集层有效渗透率的降低而变大,研究区块在油藏压力保持良好的情况下稳定产能为油藏测试产能的71.4%。To address the problem of disparity between the tested productivity and actual productivity of offshore low permeability reservoirs due to the short testing time of the exploration wells and evaluation wells,this study established a seepage mathematical model of oil-water two phases based on the law of conservation of mass and generalized Darcy formula considering the effective driving coefficient,which took into account factors including low-rate non-Darcy flow,reservoir stress sensitivity,and the maintenance level of reservoir pressure.In addition,the study also deduced productivity evaluation and prediction equations and conducted a productivity analysis using the test data of typical reservoirs in the Beibu Gulf Basin in the western South China Sea.The results are as follows:①High seepage capacity,oil-displacement efficiency,and productivity of reservoirs can be obtained by timely and effective energy supplement in low permeability reservoirs.②When the production pressure difference in the target reservoir is between 8.6 MPa and 29.5 MPa,stress sensitivity and low-rate non-Darcy flow result in a decrease in productivity by 4.0%–12.8%and 42.4%–84.4%,respectively.The influence of low-rate non-Darcy flow on productivity is much greater than that of reservoir stress sensitivity.Production wells can achieve higher reservoir productivity by amplifying production pressure difference under the premise of without sand production and without affecting the effective replenishment of reservoir energy.③The difference between the tested productivity and the stable productivity of low permeability reservoirs increases with the decrease in effective permeability.The stable productivity of the target reservoir is 71.4%of the tested productivity under the condition of maintaining reservoir pressure.

关 键 词：非达西渗流 应力敏感 油水两相 有效驱动因子 稳定产能 

分 类 号：TE348[石油与天然气工程—油气田开发工程]