液流钻井下的负压差设计与控制

Design and control of negative differential pressure in flow drilling

在地层压力系数大于 1 0 5～ 1 0 8的高压地层 ,可以用清水、盐水或密度低的钻井液实施欠平衡钻井 ,国外称为“液流钻井”(flowdrilling) ,有人也称“边喷边钻”。文中讨论了在这种情况下 ,负压差的设计原则及合理的确定钻井液密度的方法。提出了现场欠平衡钻井中如何控制设计的负压差 ,提出了切实可行的实施方法。

While drilling of formation with high pressure gradient between 1 05 and 1 08,underbalanced drilling can be done using water,salt water or low density drilling fluid.It is called flow drilling abroad,and it also called drilling while blowing-out.The paper discusses the planned rules of negative differential pressure and the methods to determine the reasonable drilling fluid density and presents how to control the negative differential pressure in underbalanced drilling in well site.Finally,the practical approaches have been got in it.