致密油藏水平井体积压裂不返排适应性评价  

Adaptability evaluation of horizontal wells without flowback after volumetric fracturing in tight reservoirs

作　　者：杨静 李成 李锦锋 龚嘉顺 梁欢 曹丹丹 张献伟 吴丹 王茜 YANG Jing;LI Cheng;LI Jinfeng;GONG Jiashun;LIANG Huan;CAO Dandan;ZHANG Xianwei;WU Dan;WANG Qian(Xiasiwan Oil Production Plant of Yanchang Oilfield Co.,Ltd.,Yan'an Shaanxi 716000,China;Research Institute of Shaanxi Yanchang Petroleum(Group)Co.,Ltd.,Xi'an Shaanxi 710065,China)

机构地区：[1]延长油田股份有限公司下寺湾采油厂,陕西延安716000 [2]陕西延长石油(集团)有限责任公司研究院,陕西西安710065

出　　处：《石油化工应用》2023年第2期27-32,共6页Petrochemical Industry Application

基　　金：延长石油科研项目“致密油藏不返排体积压裂技术先导试验”,项目编号:ycsy2019ky-B-6。

摘　　要：为论证水平井体积压裂不返排渗吸驱油工艺对研究区长8致密油藏开发的适应性,开展了储层敏感性、渗流特征、渗吸特征研究和渗吸驱油强度主控因素分析及矿场试验。结果表明:(1)长8储层速敏、水敏、盐敏、酸敏和碱敏程度均为中等偏弱,储层孔喉连续性较差和非均质性较强,基质渗流能力较低,注水驱替时油水置换效率较低,渗吸驱油强度主要受储层裂缝发育程度、缝网改造规模、渗透性和孔隙结构控制;(2)长8储层岩石润湿性以亲水-弱亲水为主,自吸驱替过程中自吸排油量高于自吸排水量,驱替排油量低于驱替排水量,压裂液流体对储层渗透性损害较弱,可采用体积压裂不返排渗吸驱油工艺开发;(3)矿场试验表明,试验井见油返排率较对比井减少12.1%,投产12个月百米水平段平均累计产油较对比井增加37.3%,平均递减率较对比井减少9.7%,有效提升了油水置换效率、延缓了递减速度和提高了原油最终采收率。该研究成果对鄂尔多斯盆地页岩油、致密油高效开发具有一定的指导意义。In order to demonstrate the adaptability of the volumetry-fractured horizontal well imbibition displacement technology to the development of Chang 8 tight oil reservoirs in the study area,the reservoir sensitivity,seepage characteristics and imbibition characteristics were studied,the influencing factors of imbibition displacement intensity were analyzed and field tests were carried out.The velocity sensitivity,water sensitivity,salt sensitivity,acid sensitivity and alkali sensitivity of Chang 8 reservoir are moderate and weak.The reservoir pore-throat continuity is poor and the heterogeneity is strong.The matrix seepage capacity is low,the oil-water displacement efficiency is low during water flooding,and the imbibition displacement intensity is mainly controlled by the development degree of reservoir fractures,the scale of fracture network reconstruction,permeability and pore structure.The rock wettability of Chang 8 reservoir is mainly hydrophilic-weak hydrophilic.In the process of self-imbibition displacement,the amount of oil discharged from self-imbibition is higher than the amount of water discharged from self-imbibition,and the amount of oil discharged from displacement is lower than the amount of water discharged from displacement.And the damage of fracturing fluid to the permeability of the reservoir is weak,so the volumetric fracturing without back drainage imbibition displacement technology can be used to develop.Compared with the comparison well,the oil flowback rate of the test well was reduced by 12.1%,the average accumulative oil production in the 100-meters horizontal section was increased by 37.3%and the average decline rate was reduced by 9.7%,which effectively improved the replacement efficiency of oil and water,delayed the decline rate of production,and improved the ultimate oil recovery.The research results have certain guiding significance for the efficient development of shale oil and tight oil in Ordos Basin.

关 键 词：不返排 渗吸驱油 储层特征 致密油藏 水平井 

分 类 号：TE345[石油与天然气工程—油气田开发工程]