高温高压对超深井钻井液密度的影响

Effects on high temperature and pressure density

井眼内钻井液密度是进行各种钻井施工和设计的必要的基础数据,高温高压环境下的超深井钻井液密度不再是一个常数,而是随温度和压力的变化而变化,因此有必要对超深井钻井中高温高压对钻井液密度的影响进行研究。利用高温高压钻井液密度模拟实验装置,采用胜科1井现场配制的超深井钻井液,测量了温度、压力对超深井水基钻井液密度的影响特性,根据测量结果,建立了温度、压力影响下的水基钻井液密度预测模型。结果表明,水基钻井液密度受温度变化影响比受压力变化影响大,随着温度、压力的增大,钻井液密度降幅较大,同时,高温高压下钻井液更具有可压缩性。建立的预测模型为合理确定现场钻井液密度范围提供了一种新方法。

In drilling operation,drilling fluid density in hole,which is not a constant but changing varying from temperature and pressure in super deep well under high temperature pressure condition,is a necessary basic data in various drilling construction and design.Therefore,it is necessary to study high temperature and pressure effects on drilling fluid density in super deep well.Influencing characteristics of temperature and pressure on water-based drilling fluid density in super deep well are measured by simulating experimental device of high temperature and pressure drilling fluid density and field preparation drilling fluid of super deep well in Shengke No.1 well.According to measuring results,density prediction model for water based drilling fluid under temperature and pressure influence is established.It shows that,the temperature effect is bigger than pressure effect on density of water based drilling fluid,and the decreasing amplitude of drilling fluid density is bigger with temperature and pressure enlarging.Meanwhile,the drilling fluid has better compressibility under high temperature and pressure.The prediction model established provides a new method for reasonable density range determination of field drilling fluid.