南堡4号构造定向井钻井液安全密度窗口的建立  

ANALYSIS OF DRILLING FLUID SAFE DENSITY WINDOW USED FOR DIRECTIONAL WELL IN 4^(TH) NANPU STRUCTURE

作　　者：刘永辉[1] 李然[1] 李路宽 靳志铁 

机构地区：[1]中国石油冀东油田公司钻采工艺研究院 [2]中国石油冀东油田工程技术处

出　　处：《钻采工艺》2014年第6期14-16,1,共3页Drilling & Production Technology

基　　金：国家科技重大专项"渤海湾盆地黄骅坳陷滩海开发技术示范工程"(编号:2011ZX05050)资助

摘　　要：受滩海环境和地面条件限制,南堡4号构造深层油藏以长位移大斜度井开发为主,在钻井实践中深部地层复杂事故率高。从井壁稳定的岩石力学机理出发,分析大斜度井井周应力分布规律,选择库仑-摩尔强度准则和最大拉应力破裂准则,计算大斜度井壁坍塌压力、破裂压力。分析了井眼轨迹随井斜、方位变化对钻井液安全密度窗口影响规律,为合理确定钻井液密度,选择最优长位移大斜度井井眼轨迹设计方案提供了科学依据,也为南堡4号构造深层低渗储层压裂改造井位合理部署提供了参考。For the limits of tidal zone and shallow water area environment and surface conditions,the deep reservoir development of the 4th Nanpu structure is mainly adopted extended-reach and high- angle deviated wells,and the complex accident rate was high in drilling operation. In order to reduce complex accident rate and increase production,the circumferential borehole stress distribution law of high- angle deviated well was analyzed based on rock mechanics of wellface stability,and the its collapse pressure and fracture pressure were calculated by using Coulomb- Mohr strength criterion and the maximum tensional stress failure criterion. The effects of well trajectory with inclination,azimuth variation on the safe density window of drilling fluid were also analyzed. These research results provided scientific basis for rationally determining the density of drilling fluid and selecting the design proposal of optimal well track of extended- reach and high- angle deviated wells,and also provided reference for deploying reasonable well placement in the4 th NanP u low permeability reservoir fracturing.

关 键 词：南堡 井壁稳定 坍塌压力 破裂压力 安全密度窗口 

分 类 号：TE254[石油与天然气工程—油气井工程]