用声波时差预测地层压力的方法

PREDICTION OF FORMATION PRESSURE WITH INTERVAL ACOUSTIC TRANSIT TIME.

本文详细推导了用声波时差计算地层压力的公式，建立了压力系数、预测压力梯度与实用泥浆比重关系图版，探讨了异常高压区成因及用区域压力趋势线加含砂校正的压力预测方法，还探讨了平衡钻进泥浆设计合理界限。本文提出的方法已在ＡＳＴ—３８６、ＡＳＴ－４８６微机上编制人机对话软件，在大港油田长芦－驴驹河地区的地层压力预测中应用，效果良好。

In this paper, the derivation of the formation pressure calculation through the interval acoustic transit time is firstly described in detail, and then a chart of formation pressure coefficient and gradient vs. practical mud density is established as well. Furthermore, the authors discussed the origin of the abnormally high pressure compartments and the rational limits of mud density in balance drilling techniques. Additionally, all the calculation methods proposed in the paper have been compiled into interactive softwares suitable to be run on the AST-386and AST-486 series computers. An application in Changlu-Luijuhe area, Dagang oilfield confirmed that these softwares are quite ideal in the prediction of formation pressure in the area.