深井重泥浆弱凝胶工艺技术初探

重泥浆强凝胶体系对钴井会产生不利影响。笔者结合川东地区的实际情况,分析了重泥浆强凝胶形成的原因和重泥浆弱凝胶的形成机制,提出了形成重泥浆弱凝胶体系的核心和设计原则,总结出了一套以正确使用泥浆添加剂并配合强有力的固控措施为主的成套深井重泥浆弱凝胶工艺技术,介绍了这套技术在川东地区的应用情况。实践证明,少用甚至不用泥浆降粘剂就可获得并维持尽可能低的静切力,使τ_s,10s为0.5—6Pα、τ_s,10min为2—12.5Pα。

A PRELIMINARY STUDY ON TECHNOLOGICAL ASPECT OF WEAKLY GELLING HEAVY MUDS FOR DEEP WELL DRILLING

On the basis of analyzing the formation of strong and weak gels in heavy muds for deep well drilling in East Sichuan area,this paper presents the kernel problem and principles in designing weakly gelling heavy muds and recommends a complex mud technology for whole deep well drilling which covers, besides efficient solid phase control,the proper usages of various mud additives and mud conversions: from solidfree polymer mud to non-dispersed low-solid multi-polymeric collapse-prevented mud and further to coarse-dispersed polymer mud or to sulfonated light mud, the later is treated and weighted.The polymeric additives must be carefully optimized, any dispersant be excluded,the pH values and bentonite contents maintained at possibly low levels. The composition and the conversion of the muds are described.The above understandings and designing principles of weakly gelling heavy muds for deep well drilling are evidenced by the successful field results of using this mud technology.