七里村油田长6致密油藏流动单元评价及压裂选层

Flow Unit Evaluation and Fracturing Layer Selection in Chang 6 Tight Reservoir of Qilicun Oilfield

为选取压裂水平缝合适位置,制定合理开发方案,解决鄂尔多斯盆地北部七里村油田水窜严重、产量极低的问题,选取七里村油田长6致密油藏的羊圈山M井组,对主力层位长61和长62进行了流动单元划分。介绍了储层流动单元的划分原则、划分方法和评价方法,选取了孔隙度、渗透率、含油饱和度、流动带指数、渗流系数等五个参数,对羊圈山M井组5口生产井的流动单元进行划分和评价,分析了每口井的Ⅰ类、Ⅱ类和Ⅲ类流动单元的分布情况,以及每口井压裂层位与Ⅰ类、Ⅱ类和Ⅲ类流动单元的匹配情况。提出了压裂改造措施层位的选取原则和建议:优先选取流动单元横向连通性好的层位进行压裂;主力含油层位(包含多个优质流动单元且含油性好)必须压裂;在压裂层位有限的前提下,应优先选取Ⅰ类流动单元,至少是Ⅱ类流动单元作为压裂对象。

Serious water channeling and extra-low oil production appeared in Qilicun oilfield in northern Or-dos Basin.In order to select suitable horizontal fracture position and work out rational development plan,the flow units in major pays Chang 61 and Chang 62 were classified in M well group of Yangquanshan zone of Chang 6 tight reservoirs in Qilicun oilfield.Classification principle and method and evaluation method of the flow units were introduced.Five parameters including porosity,permeability,oil saturation,FZI and flow index were selected to classify and evaluate the flow units in five production wells of M well group,Yangquanshan.Distribution of class Ⅰ,class Ⅱ and class Ⅲ flow units in each well was analyzed,as well as corresponding fracturing layer.Selection principle and suggestion of fracturing layers was put forward.The layer with good cross connection in the flow unit may be selected first to fracture.Major pays（including multiple good-quality flow units with good oil-bearing property） must be fractured.Under the condition of limit fracturing layers,class Ⅰ flow units should be selected first,and then class Ⅱ flow unit as the object of fracturing.