神木-双山区块安全钻完井技术研究与应用

Research and application of safe drilling and completion technology in Shenmu Shuangshan block

为长庆油田为实现年产油气当量突破6000万t目标,加大了神木-双山区块油气田的开发,但钻井提速成为油气田开发的技术瓶颈,神木-双山区块存在多套易塌地层,特别是延长组和双石层地层含有大段易塌地层。由于泥页岩中含有水敏性黏土矿物,当与钻井液接触时,泥页岩与钻井液相互作用,产生水化膨胀,不仅改变了井眼周围的应力分布,而且由于吸水使得泥页岩的强度降低,导致泥页岩地层的井壁失稳问题非常严重。双山神木区块与其他区块地层差异比较大,很成熟的钻井液体系并不能完全满足此区块钻井要求,本文从井壁失稳分析并结合本区块特点,提出了关于神木-双山快速钻完井安全技术。

In order to achieve the goal of annual oil and gas equivalent exceeding 60 million tons in Changqing Oilfield, the development of oil and gas fields in Shenmu Shuangshan block has been increased, but the increase of drilling speed has become the technical bottleneck of oil and gas field development. There are many sets of collapsible strata in Shenmu Shuangshan block,especially large sections of collapsible strata in Yanchang Formation and Shuangshi formation. Due to the water sensitive clay minerals in shale, when it comes into contact with drilling fluid, shale and drilling fluid interact to produce hydration expansion,which not only changes the stress distribution around the wellbore, but also reduces the strength of shale due to water absorption,resulting in serious wellbore instability in shale formation. The formation of Shuangshan Shenmu block is quite different from other blocks, and the mature drilling fluid system can not fully meet the drilling requirements of this block. Based on the wellbore instability analysis and combined with the characteristics of this block, this paper puts forward the safety technology of Shenmu Shuangshan fast drilling and completion.