扩展安全密度窗口钻井液技术在吐哈油田的应用

The Application of the Drilling Fluid Technology of Extending the Safe Density Windows in Tuba Oilfield.

介绍了吐哈油田使用的2种扩展安全密度窗口防漏堵漏钻井液技术。一种是针对丘陵区块高压调整井提高钻井液密度时引发的漏失问题,从提高钻井液的封堵造壁能力及改善高密度钻井液的润滑性和流变性入手,形成的一套防漏技术。另一种是针对吐哈钻井公司承钻的塔河油田盐下井提高钻井液密度时引发的漏失问题,形成的一套承压堵漏技术,该技术使用的堵漏剂由粗、中、细及软、硬堵漏材料按照合理匹配复配而成。介绍了2种防滑堵满钻井液技术的现场施工工艺。推广应用结果表明,扩展安全密度窗口的防漏堵满钻井液技术,能有效提高地层承压能力,减少井下漏失,缩短钻井周期。

This paper introduced two methods of extending the safe density windows of drilling fluids in preventing and controlling mud losses in Tuha Oilfield:the first method is aimed at solving the mud losses caused by increased mud densities in foothill area drilling,and the second one is aimed at dealing with the mud losses caused by in- creased mud densities in drilling formations beneath salt domes in Tarim river area.The first method focused on the improvement of the sealing capacity,lubricity and rheology of the drilling fluids,while the second method em- phasized the use of sized lost circulation materials(LCM)with different hardness.The techniques of using the two methods were discussed in the paper.Filed application showed that extending safe density windows of drilling flu- ids can greatly increase the pressure containment of formations drilled,and thus minimize mud losses and shorten drilling times.