硅酸钾钻井液在页岩气水平井中的可行性研究

Feasibility Study of Potassium Silicate Drilling Horizontal Wells in Shale Gas

摘要:

页岩气开发以水平井为主，由于页岩地层裂缝与层理发育，在长水平段钻井过程中极易发生垮塌等井眼稳定问题，同时还有携岩、摩阻等一系列问题；大量的研究工作表明，硅酸盐钻井液的抑制性是较为接近油基钻井液体系的，但其能否用于页岩气水平井的钻井过程中是值得探讨的。本文在对硅酸盐钻井液体系及页岩稳定分析的基础上，建立了一套硅酸钾钻井液体系，该钻井液体系除了具有良好的抑制性能以外，更具有较低的滤失量(高温高压滤失量＜6 mL)，并且流变性易于控制，润滑性好，分析认为该体系能够满足页岩气水平井钻井的要求。

Abstract:

The mainly of shale gas development are horizontal wells, due to fracture and bedding developed in shale formation, collapse and other wellbore stability problems can easily occur in the process of drilling long horizontal sections, as well as carrying rocks, friction and other issues; A lot of research work surface silicate drilling fluid inhibition is closer to the oil-based drilling fluid system, but it can be used during drilling horizontal wells in shale gas is worth exploring. On the basis of silicate drilling fluid system and shale stability analysis, the establishment of a potassium silicate drilling fluid system, beside a good suppression performance outside, the drilling fluid system having lower fluid loss (high temperature and high pressure loss is less than 6mL), and easy to control rheology, good lubrication, analysts believe that the system can meet shale gas horizontal drilling requirements.