基于水平井约束下的致密砂岩储层精细描述方法  

A fine description method for tight sandstone reservoirs based on horizontal-well constraints

作　　者：蒙晓灵 张芳[1,2] 夏守春[1,2] 蒙学东 刘雪玲[1,2] Meng Xiaoling;Zhang Fang;Xia Shouchun;Meng Xuedong;Liu Xueling(Exploration and Development Research Institute,PetroChina Changqing Oilfield Company,Xi’an,Shaanxi 710018,China;National Engineering Laboratory for Low-permeability Oil&Gas Exploration and Development,Xi’an,Shaanxi 710018,China;No.1 Gas Production Plant,PetroChina Changqing Oilfield Company,Xi’an,Shaanxi 710021,China)

机构地区：[1]中国石油长庆油田公司勘探开发研究院,陕西西安市710018 [2]低渗透油气田勘探开发国家工程实验室 [3]中国石油长庆油田公司第一采气厂

出　　处：《天然气勘探与开发》2022年第4期96-102,共7页Natural Gas Exploration and Development

基　　金：国家科技重大专项“复杂天然气藏开发关键技术”(编号:2016ZX05015)。

摘　　要：近年来,随着苏里格气田的开发,鄂尔多斯盆地已经率先进入“非常规”资源开发时代,水平井成为提高致密砂岩气藏单井产量的主要技术手段。特有的黄土塬地貌导致地震预测的砂体厚度符合率低,而通过密井网解剖砂体在一定程度上能提高砂体展布认识的精度,但局部沉积的分流河道砂体横向迁移较为频繁,在水平井实施过程中常发生侧出河道的情况,降低了储层钻遇率。为此进行了水平井约束下的致密砂岩精细描述技术优化:(1)充分利用水平井水平段资料降低井间盲区,提高砂体描述精度;(2)依据水平井实钻轨迹资料建立“有效储层长度”大数据库,可降低水平井实钻侧出河道的风险;(3)利用出发井和末端控制井资料,首先进行各井点砂体对比和结构分析,初步识别单砂体,然后基于水平井实钻资料对原有砂体描述进行补充和约束,进行井间砂体平面展布预测,最后在建立大数据的基础上完成砂体空间立体描述,达到水平井约束下的砂体精细描述。With the development of Sulige gasfield, Ordos Basin has first entered an era to exploit “unconventional” oil and gas resources. And horizontal wells serve as an essential drilling tool to raise single-well production in tight sandstone gas reservoirs. Exclusive loess plateau landform may create a low coincidence rate of sandbody thickness from seismic prediction, and sandbody dissecting through dense well spacing can improve an accuracy in understanding sandbody development to a certain extent. Nevertheless, part sandbodies deposited at distributary channel migrate in the lateral very frequently and lateral channeling usually emerges at the time of horizontal-well drilling to lower a penetration ratio. Therefore, one technology of fine description was optimized for sandstone reservoirs under horizontal-well constraints, including that(1) data on horizontal intervals are adequately used to reduce interwell blind and improve description accuracy,(2) an “effective reservoir length” database is established according to real data on drilling trajectory so as to reduce risk in the lateral channeling, and(3) data on both starting and terminal controlling wells are utilized. Sandbodies inside each well are compared and analyzed for preliminarily identifying single sandbody;then their original description is complemented and constrained dependent upon actual drilling data to predict planar sandboby distribution among wells;and finally the sandbody is finely described in 3D space according to the established big data.

关 键 词：致密砂岩气藏 砂体精细描述 井间盲区 水平井约束 有效储层长度 苏里格南区 

分 类 号：TE321[石油与天然气工程—油气田开发工程]