摘要
环空压力对可循环泡沫控制压力钻井来说是一个重要的参数,但在钻进过程中要获得此参数比较麻烦。为此,建立了一套利用求得动密度及环空流动压耗并根据静液柱压力最后得出可循环泡沫钻井环空压力的计算模型,其理论计算结果与环空压力实测情况对比分析表明,井底压力的理论计算误差小于1.5%,理论计算值与实测值基本一致,表明此计算方法对可循环泡沫钻井有一定的适用性。进行了可循环泡沫钻井与常规钻井液钻井环空压力的对比分析,结果表明在3000m井深处,采用可循环泡沫钻井比常规钻井液钻井的环空压力低2～3MPa,说明可循环泡沫钻井能降低钻井时的井底压力,以达到降低储层伤害的目的。
Annulus pressure is an important parameter for both circulative-foam and controlled pressure drilling. But it is hard to be obtained. Therefore, a set of computational models, which are used to calculate annulus pressure through derived dynamic density, annular flow pressure loss and hydrostatic fluid column pressure, is established. A comparative analysis between calculated and measured results shows that a calculation error of bottomhole pressure is less than 1.5 % ; the calculated value is basically consistent with the measured one. It is also shown that this calculation method has some applicability for circulative-foam drilling. Another comparative analysis is also conducted between the annulus pressure of circulative-foam drilling and that of conventional drilling-fluid drilling. The result shows that at well depth of 3000m, the annulus pressure of circulative-foam drilling is lower than that of conventional drilling-fluid drilling by 2-3 MPa, which indicates that circulative-foam drilling can decrease bottomhole pressure to reduce formation damage.
出处
《天然气技术》
2010年第5期38-40,63,共4页
NATURAL GAS TECHNOLOGY
基金
川庆钻探工程有限公司科技攻关项目"长庆气田可循环泡沫控制压力钻井技术研究与应用"(编号:2009-54)中的部分研究内容
关键词
可循环泡沫钻井
控制压力钻井
环空压力
静液柱压力
井底压力
降低储层伤害
circulative-foam drilling, controlled-pressure drilling, annulus pressure, hydrostatic fluid column pressure, bottomhole pressure, formation-damage reduction
