长北大井眼大斜度井段钻井液体系改进与实践

长北区块率先在长庆区域二开井段采用Ф311.1 mm大井眼,在生产实践中存在以下钻井液技术难题:二开大井眼段大斜度段井壁稳定问题、大井眼防漏堵漏问题、大井眼井壁润滑和煤层段坍塌等问题。从长北项目开始至今,本着环保第一、降本增效的主旨对钻井液进行了一系列的优化和改进。先后使用了清水聚合物体系和低固相三磺聚合物体系。但是由于这两种体系对斜井段的抑制性和防塌性不足,导致黏土分散、膨胀、垮塌和钻头泥包问题。本文介绍了一种在上述体系的基础上,经过不断的优化和改进,形成的应用于长北区块Ф311.1 mm斜井段的强抑制防塌一体化钻井液体系。室内实验数据和现场应用表明,该钻井液体系具有维护简单、防塌抑制性强的特点,大幅度降低了生产成本、最大化的延长了井壁的坍塌周期,增加了井壁稳定性和预防了PDC钻头泥包,在使用过程中创造了多项钻井纪录,节省了大量的非生产时间,创造了很可观的经济效益。

Big hole big slope section drilling fluid system improvement and practice in Changbei

Changbei block took using the Ф 311.1 mm big hole firstly in the Changqing area.In the production practice, there are several problems in the drilling fluid technology, large slope section sidewall stability problems, the big hole plugging problem, the big hole wall lubrication and coal section problems such as collapse and so on. Since the start of the Changbei project, for the environmental protection purpose and reducing cost and for drilling fluid, conducted a series of optimization and improvement. We successively used water polymer system and low solids three sulfonated polymer system. But because the two systems of inclined shaft section inhibitory and prevent collapse resistance is insufficient, lead to clay dispersion,expansion,collapse and bit balling up problem.This paper introduces a kind of the system based on through continuous optimization and improvement, form used in Changbei block Ф 311.1 mm slope section of strong inhibition collapse prevention integrated drilling fluid system. Indoor experimental data and field application show that the drilling fluid system has simple maintenance, prevent collapse inhibitory strong characteristic, reduced the production cost, maximum extended the casing collapse cycle, increase the sidewall stability and prevent the PDC bit balling, in use process created many drilling records, save a lot of non-productive time, creating a very considerable economic benefits.