基于控制水驱前缘速度的注采井组参数优化方法研究与应用  

Research and application of optimization method for injection and production well group parameters based on controlling waterflood front velocity

作　　者：刘芳娜 高涛 王锰 凃兴平 李玮 施里宇 张亮 赵倩 LIU Fangna;GAO Tao;WANG Meng;TU Xingping;LI Wei;SHI Liyu;ZHANG Liang;ZHAO Qian(Research Institute of Shaanxi Yanchang Petroleum(Group)Co.,Ltd.,Xi’an 710065,China)

机构地区：[1]陕西延长石油(集团)有限责任公司研究院,西安710065

出　　处：《非常规油气》2024年第2期108-117,共10页Unconventional Oil & Gas

基　　金：国家重点基础研究发展计划(973计划)项目“致密油高效开发油藏工程理论与方法研究”(2015CB250905)。

摘　　要：低渗致密油藏注水开发与中高渗油藏不同,井组见效极其不均衡导致无效注水是造成水驱采收率低的主要原因,有必要形成1套以油井同步见水为目标的注采参数调整方法来指导现场注水调整。结合延长油田低渗致密且油水混储的实际情况,建立了考虑毛细管力作用的平面分区径向流水驱前缘推进数学模型;通过优化注水强度与注采压差,形成了两端注采结构调整方法;定量研究了影响井组均衡水驱的3个关键因素。结果表明:通过调整注采井距和注采压差可有效解决渗透率级差导致的平面水驱不均衡的问题;当f w<60%时注采井距比对井组采出程度的影响较大,渗透率级差为20时对应的最佳注采井距比为1.5~2.0。对于注采井网固定的开发老区,主要通过控制各油井方向的生产压差来控制水驱前缘速度。基于两端注采参数调整方法,将D4430-8井组内注水井注水强度从1.87 m^(3)/(d·m)提高到2.50 m^(3)/(d·m),并通过调整3口油井的泵挂来改变注采压差。调整之后D4430-8井组综合含水由37.80%下降至25.29%,单井平均日产油量增加0.53 t,水驱开发效果明显改善。研究结果对低渗致密油藏注水开发老区改善平面波及效率具有重要指导意义。The water injection development of low permeability/tight reservoirs differs from that of medium-high permeability reservoirs.The unbalanced effectiveness of well groups leads to ineffective water injection,which is the main reason for low waterflood recovery.It is necessary to form a set of injection and production parameter adjustment methods with the goal of synchronous breakthroughs in oil wells to guide the on-site water injection adjustment.Combined with the actual situation of low permeability/tight reservoirs with mixed oil and water storage in Yanchang Oilfield,the authors established a mathematical model for waterflooding front of zonal radial flow considering the capillary force.A dual-end injection and production structure adjustment method was formed by optimizing the injection and production pressure difference and the water injection intensity.The authors quantitatively studied three key factors affecting the balanced waterflood of well groups.The results indicate that adjusting injection production well spacings and injection production pressure differences could effectively solve the problem of unbalanced planar waterflood caused by a large permeability ratio;when f w<60%,the injection and production well spacing ratio has a significant impact on the well group recovery.When the permeability ratio is 20,the optimal injection and production well spacing ratio is 1.5~2.0 For mature development areas with fixed injection and production well patterns,the waterflood front velocity is mainly controlled by controlling the production pressure difference in each oil well direction.Based on the adjustment method of injection and production parameters at both ends,the injection intensity of injection wells in well group D4430-8 was increased from 1.87 m^(3)/(d·m)to 2.50 m^(3)/(d·m),and the injection and production pressure differences were changed by adjusting the pump setting depths in three oil wells.After the adjustment,the comprehensive water cut of well group D4430-8 decreased from 37.8%to 25.29%,and

关 键 词：注采参数 均衡水驱 非活塞两相水驱油 分区径向流数学模型 低渗致密油藏 

分 类 号：TE312[石油与天然气工程—油气田开发工程]