摘要
苏里格气田盒8下亚段气藏纵向多期河道砂体依次切叠,横向同一期次内不同河道砂体相互拼接、同一河道内辫状水道砂体与心滩砂体交错切割,形成了层次复杂的辫状河储层。沉积层次的复杂多样导致储层内部发育不同层次的隔夹层,其产状、规模及发育位置均存在较大差异。正确识别并＂有效避开＂这些隔夹层从而达到提高砂体钻遇率的目的是辫状河储层水平井地质导向的重点和难点。以苏里格气田中区下二叠统石盒子组盒8下亚段储层为研究对象,运用Miall的储层构型基本理论,将研究区隔夹层划分为3个层次：1垂向层间隔层;2侧向河间泛滥泥;3单砂体内部夹层。对不同层次隔夹层进行了成因分析,分别阐述了其空间分布、测井响应特征,在此基础上提出了相应的水平井地质导向策略：钻遇垂向层间隔层适当角度（〈1.5°）穿越泥岩;钻遇侧向河道间泥质体大角度（2°-3°）快速穿越或实施侧钻;钻遇单砂体内部夹层略微调整井斜（〈0.5°）。2014年该套方法在苏里格气田某区块进行现场应用,与邻区相比砂岩钻遇率、有效储层钻遇率分别提高了5%和3%,具有一定的推广价值。
The reservoir of Lower 8th member of Shihezi Formation in Sulige Gasfield has multistory braided river channel sandbodies which cut and superimpose in turn vertically,and in horizontal direction,many channel sandbodies interleave pieces together,otherwise braided distributary channel sandbodies and braidbar sandbodies cross-cut each other in the same braided channel,and braided river reservoirs can be characterized by complex hierarchy.How to understand and effectively avoid this interlayer to improve the drilling rate of sandbody is a problem.Taking the reservoir of Lower 8th member of Shihezi Formation in Sulige Gasfield as an example,the reservoir architecture theory of A.D.Miall guides us to divide the interlayer into three levels,the vertical bay level,the lateral flooding mud of inter channel and the inter layer of single sand body.Analyzing the cause of different inter layers,the spatial distribution and the logging response characteristics,on the base of the study mentioned above,the geosteering strategy of horizontal well is established.The vertical bay type uses a proper angle（1.5°）to drill through the mudstone.A larger angle（2°-3°）is used to cross the mud stone or carry out the side tracking in the lateral flooding mud of inter channel.As for the interlayer of the single sandbody,a little bit adjustment（0.5°）of the well deviation would be efficient.This theory is used in an area of Sulige Gasfield in 2014.Compared with the nearby area,the drilling ratio of sandstone and effective reservoir is raising up to 5% and 3%,respectively.
出处
《天然气地球科学》
EI
CAS
CSCD
北大核心
2016年第8期1380-1387,共8页
Natural Gas Geoscience
基金
国家重大科技专项"鄂尔多斯盆地大型低渗透岩性地层油气藏开发示范工程"(编号:2016ZX05050)资助
关键词
隔夹层
层次分析
辫状河储层
水平井
地质导向
产状
苏里格气田
鄂尔多斯盆地
Braided river reservoir
Inter layer
Hierarchical analysis
Horizontal well
Geosteering
Attitude
Sulige Gasfield
Ordos Basin
