巨厚生物碎屑灰岩油藏大斜度井开发井网模式——以伊拉克H油田Mishrif油藏为例

Well Pattern for Develoment of Giant Bioclastic Limestone Reservoir by Highly Deviated Wells:A Case Study of Mishrif Reservoir of H Oilfield in Iraq

以伊拉克H油田Mishrif油藏为例,探索了大斜度井技术在井网部署中的应用。基于Besson产能公式绘制了井型选择图版,应用数值模拟方法对大斜度井长度和井型结构进行了优化设计,建立了“直井注水+大斜度井采油,注采井交错排状部署”的井网模式,形成了一套巨厚生物碎屑灰岩油藏开发井网部署技术。结果表明:采用斜井段开采Mishrif油藏上部低渗层、水平段开采下部高渗层可以充分发挥井型优势,实现不同物性储集层均衡开采;大斜度井最优长度在940 m左右,斜井段与水平段长度的分配比例在2∶1左右;井网调整过程中应规避和有效利用隔夹层。

Taking Mishrif reservoir in H oilfield of Iraq as an example,the application of high deviation well technology in well pattern deployment is explored.The well type selection chart is drawn based on Besson productivity formula,and the length and structure of highly deviated wells are optimally designed by numerical simulation method.A well pattern form of"water injection in vertical wells,oil production in highly deviated wells and staggered arrangement of water injection and production wells"is established,and a set of well pattern deployment techniques for development of giant bioclastic limestone reservoirs are formed.The application result shows that to exploit low permeability layer in the upper of Mishrif reservoir by means of inclined section and to exploit high permeability layer in the lower of Mishrif reservoir by means of horizontal section can give full play to the advantages of highly deviated well and realize the balanced exploitation of the reservoirs with different physical properties.The optimal length of highly deviated wells is 940 m,and the length ratio of deviated section to horizontal section is about 2:1.Interlayers should be avoided or effectively utilized in well pattern adjustment.The well pattern form of high inclined wells helps H oilfield to build up 10 million tons of annual productivity scale quickly.The research result can provide technical reference for the development pattern deployment of similar oilfields at home and abroad.