在线核磁监测法优化裂缝性页岩油藏赋能渗吸吞吐工艺  

Optimization of fractured shale oil energized imbibition huff and puff process by on-line nuclear magnetic resonance monitoring method

作　　者：陈洪才[1] 王彪[2] 李太伟[2] 张鑫[2] 朱杰 戴志鹏 孙敬[3] 李思辰 CHEN Hongcai;WANG Biao;LI Taiwei;ZHANG Xin;ZHU Jie;DAI Zhipeng;SUN Jing;LI Sichen(No.2 Oil Production Plant of SINOPEC Jiangsu Oilfield Company,Huaian 211600,Jiangsu,China;Petroleum Engineering Technology Research Institute of SINOPEC Jiangsu Oilfield Company,Yangzhou 225009,Jiangsu,China;College of Petroleum Engineering,Yangtze University,Wuhan 430100,Hubei,China)

机构地区：[1]中国石化江苏油田分公司采油二厂,江苏淮安211600 [2]中国石化江苏油田分公司石油工程技术研究院,江苏扬州225009 [3]长江大学石油工程学院,湖北武汉430100

出　　处：《石油钻采工艺》2024年第2期228-237,共10页Oil Drilling & Production Technology

基　　金：中国石化江苏油田分公司基础前瞻项目“页岩油赋能渗吸强化采油技术前瞻研究”(编号:JS21025)。

摘　　要：赋能渗吸采油可以通过补充地层能量、置换等方式提高原油采收率,目前已成为页岩油藏开发的重要技术。设计合理的赋能渗吸工艺参数,可以更高效地开发页岩油藏。通过4轮次赋能渗吸吞吐实验,利用在线核磁技术分析纳米级原油微观运移特征,优化了裂缝性页岩油藏焖井时间、赋能时机、吞吐轮次等赋能渗吸工艺参数。实验结果表明,首次焖井时间控制在12~15 d即可,随着吞吐轮次的增加,焖井时间应相应减少;吞吐3轮次后对采收率的提升作用不明显,具有明显的有效轮次;压力下降至原始地层压力70%后,继续控压生产效果较差,需及时对地层进行补能,以保证页岩油井高效开发;赋能渗吸时不同液体注入量对采出油量有较大影响,注入量偏少,补充能量不充分,采出效果不佳;但由于储层渗透率极低,补充能量作用半径有限,补能流体量不能无限增加,一般达到压裂裂缝控制体积的0.4 PV左右即可。研究结果可为页岩油藏赋能渗吸工艺参数优选提供技术支撑。As currently important technology for shale oil reservoir development,energized imbibition oil recovery method can improve crude oil recovery efficiency by replenishing formation energy and replacing reservoir crude oil.Reasonable design of energy-enabled imbibition process parameters can develop shale reservoirs more efficiently.In this paper,four rounds of huff and puff experiments are conducted,on-line nuclear magnetic resonance technology is used to analyze the microscopic migration characteristics of nano-scale crude oil,and thus,the reasonable soaking time,empowerment timing,huff and puff rounds and other empowerment imbibition process parameters of fractured shale oil reservoirs are optimized.The experimental results show that the first soaking time can be controlled within 12~15 days,and the soaking time should be reduced accordingly with the increase of throughput rounds.After 3 rounds of huff and puff,the effect on improving oil recovery is not obvious with evidently effective rounds.After the pressure drops to 70%of the original formation pressure,the production effect by continuous pressure reduction is poor,which requires to replenish the formation in time to maintain the efficient development of shale oil wells.Different liquid injection volume has greater effect on the amount of produced oil when energized.If the injection volume is too low,the energy supplement is not sufficient,resulting in worse recovery effect.However,due to the extremely low permeability of the reservoir,the radius of the supplementary energy is limited,and the amount of injected supplementary fluid cannot be increased indefinitely.Reaching about 0.4 PV of the induced fracture control volume is generally acceptable.This research offers technological foundation for parameters optimization of shale oil reservoir energized inbibition technology.

关 键 词：页岩油 微裂缝 在线核磁共振 焖井时间 赋能渗吸 吞吐时机 工艺优化 

分 类 号：TE34[石油与天然气工程—油气田开发工程]