论直井-水平井混合井型开发陆相/海陆过渡相页岩气的优势  

Advantages of hybrid well types including both vertical and horizontal wells to develop continental and transitional shale gas

作　　者：张涛[1] 李相方[1] 王香增[2] 唐永槐 里清扬 王小华 冯东[1] 赵文 ZHANG Tao;LI Xiangfang;WANG Xiangzeng;TANG Yonghuai;LI Qingyang;WANG Xiaohua;FENG Dong;ZHAO Wen(Key Laboratory for Petroleum Engineering of the Ministry of Education,China University of Petroleum-Beijing,Beijing 102249,China;Shaanxi Yanchang Petroleum(Group)Corp.Ltd.,Xi’an 710065,China;Research Institute of Shaanxi Yanchang Petroleum(Group)Corp.Ltd,Xi’an 710065,China;Heavy Oil Company Liaohe Oilfield Petro China,CNPC,Panjin 124010,China;Key Laboratory of Geotechnical&Underground Engineering of Ministry of Education,Tongji University,Shanghai 200092,China)

机构地区：[1]中国石油大学(北京)石油工程教育部重点实验室,北京102249 [2]陕西延长石油(集团)有限责任公司,西安710065 [3]陕西延长石油(集团)有限责任公司研究院,西安710065 [4]辽河油田特种油开发公司,盘锦124010 [5]同济大学岩土与地下工程教育部重点实验室,上海200092

出　　处：《石油科学通报》2021年第2期272-281,共10页Petroleum Science Bulletin

基　　金：国家自然基金面上项目“页岩气有效储渗孔隙跨尺度耦合渗流及产出规律研究”(编号:50974128);国家科技重大专项“陆相页岩气产能评价与采气工艺技术”(编号:2017ZX05039005)联合资助。

摘　　要：长水平井+体积压裂是海相页岩气开发取得成功的主流技术,但我国的陆相/海陆过渡相页岩与海相页岩储层性质相差较大,陆相/海陆过渡相页岩的开发方式不能照搬海相页岩气的。本文提出陆相/海陆过渡相页岩应采用直井和水平井混合井型开发的技术思想。该技术思想的关键出发点在于陆相/海陆过渡相页岩(1)脆性矿物含量少,水平井体积压裂造复杂缝困难;(2)黏土矿物含量高,水平井体积压裂储层污染面积大;(3)纵向往往伴生其它非常规天然气资源(致密气、煤层气等),采用直井“多气合采”可以控制更多的储量。以鄂尔多斯盆地延长探区为例,本文详细论证了陆相/海陆过渡相页岩的上述特征对直井和水平井开发的影响,提出了基于水平井可控纵向储量占比、脆性指数、储层伤害表征参数和薄砂层占比4个参数的合理井型优选标准。结果表明,当水平井可控纵向储量占比<60%,脆性指数<35%,储层伤害表征参数>20%,薄砂层占比<10%时,可以采用直井开发,反之采用水平井开发。进一步地,基于该标准分析了延长组长7段和山西组山1段陆相页岩水平井与直井的开发实例。本文提出的思想突破了水平井是实现页岩气开发唯一方式的传统认识,强调了直井联合水平井开发陆相/海陆过渡相页岩气的优势,为实现陆相/海陆过渡相页岩气的经济有效开发奠定基础。Long horizontal wells combined with multi-stage hydraulic fracturing make it possible to successfully develop marine shale.However,the geological characteristics of continental or transitional shale in China are significantly different from those of marine shale,and the successful techniques used in marine shale cannot be directly applied during the development of continental or transitional shale.In this work,we proposed that vertical wells can be combined with horizontal wells to develop continental and transitional shale.The reasons for this technical suggestion include that continental and transitional shale(1)usually contain a low proportion of brittle minerals,which results in relatively simple fractures created during the multi-stage hydraulic fracturing;(2)usually contain a high proportion of clay minerals,and the amount of formation damage due to the invasion of fracturing fluid during the multi-stage hydraulic fracturing is high,compared with formation damage for vertical wells;(3)usually co-exist with other types of unconventional gas in other formations vertically(tight gas,coal-bed methane,etc.),and commingling production together from these unconventional gas layers by using vertical wells can control more reserves.Using the geological and production data from the Yanchang Petroleum Group in the Ordos basin,China,we analyzed in detail the effects of the aforementioned characteristics on the production performance of shale gas wells by using vertical completion and horizontal completion.In addition,four characterization parameters including vertical reserve index(the ratio of reserves controlled by horizontal wells and that controlled by vertical wells),brittleness index,formation damage index and silty laminae index were proposed to help the decision makers/operators to select the optimal well type.The results show that,when the vertical reserve index is smaller than 60%,brittleness index is smaller than 35%,formation damage index is larger than 20%and silty laminae index is smaller than 10%,it is r

关 键 词：陆相页岩气 井型 可压性 储层伤害 多气合采 

分 类 号：TE377[石油与天然气工程—油气田开发工程]