提高窄密度窗口钻井可操作性的井下工具探讨  

Discussion on Downhole Tool to Improve Drilling Maneuverability in Case of Narrow Density Windows

作　　者：祝效华[1,2] 王宇[2] 童华[2] 

机构地区：[1]西南石油大学油气藏地质及开发工程国家重点实验室 [2]西南石油大学机电工程学院,成都610500

出　　处：《石油矿场机械》2009年第11期69-71,共3页Oil Field Equipment

基　　金：国家自然科学基金资助项目"气体钻井钻具与井壁的碰撞机理及量化评价方法研究"(50804040);PLN国家重点实验室开放基金项目"气体钻井钻柱振动机理研究"(PLN0701);四川省教育厅自然科学基金项目"气体钻井钻具频繁失效的力学机理分析";西南石油大学青年科技基金项目(2007XJZ093)

摘　　要：在油气田钻井中钻井泥浆形成的压力介于坍塌压力和破裂压力之间,否则井眼岩石容易出现坍塌或破裂。在部分深井中,密度窗口很窄且钻井泥浆的当量循环密度曲线靠近破裂压力曲线,很容易造成喷、塌、卡等事故。提出了一种减小钻井泥浆环空循环压耗的井下工具,介绍了该工具的结构、工作原理、技术参数。该工具使用方便,可有效降低裸眼井段的环空循环压耗,提高窄密度窗口工况下钻井的可操作性。During the oil-field drilling process, it was required that the pressure formed by drilling fluid in drilled wells fall in between the collapse pressure and the fracture pressure, otherwise rock in the borehole would be prone to collapse or fracture. In some deep wells, the density windows was so narrow and the equivalent circulating density curve of the drilling fluid was so close to the fracture pressure curve that it was prone to the accidents of blowout, collapse, stuck drill and so on. Therefore, a downhole tool that can reduce the annular cyclic pressure loss and intro- duced its structure, principle of work and technical parameters were put forward. This kind of tool is easy to use, and it can lower the annular cyclic pressure loss efficiently in the barefoot interval and improve the drilling maneuverability in the case of narrow density windows.

关 键 词：坍塌压力 破裂压力 窄密度窗口 环空循环压耗 井下工具 

分 类 号：TE921.202[石油与天然气工程—石油机械设备]