基于轨迹优化扩展大位移井窄安全密度窗口
发布时间：2019-07-24 12:31
【摘要】：S区块位于俄罗斯萨哈林岛东部海域,计划采用大位移井海气陆采技术进行开发。该区设计井深达12 000 m(垂深为2 800 m),水平位移约11 000 m,水平位移与垂直深度之比达3.93,初步设计四开井身结构。以往直井钻探表明,该区奥科贝凯组(Okobykaiskiy)下部及达吉组(Daginskiy)地层安全钻井液密度窗口窄(约0.3~0.4 g/cm3)、漏、塌、卡风险高,而大位移开发井相应井段窄安全密度窗口问题愈加突出。针对当前对于扩展窄安全密度窗口相关研究的不足、特别是局限于通过钻井液性能优化扩展安全密度窗口的现状,围绕窄安全密度窗口大位移井钻井难题,提出应综合力学、化学多手段全方位扩展窄安全密度窗口:首先,自井眼轨迹设计环节将优化井身剖面、改善井周围岩应力状态、扩展安全密度窗口有机结合起来,开展井眼轨迹主要参数对安全密度窗口的影响规律分析,在此基础上,兼顾井眼轨迹控制难度及施工摩阻等因素优化井眼轨迹,降低坍塌压力、提高地层破裂压力,实现安全密度窗口的先期扩展,为后续通过优化钻井液性能等手段进一步提高安全密度窗口奠定良好基础,并最终为窄安全密度窗口安全、高效钻井创造有利条件。研究形成的扩展密度窗口相关技术在S区块大位移井钻井设计中成功应用,使得目标层段安全密度窗口较轨迹优化前扩展幅度达25%~100%,对窄安全密度窗口难题的应对及防治具有指导意义。
[Abstract]:S block is located in the eastern sea area of Sakhalin Island in Russia and plans to be developed by sea-air and land mining technology in large displacement wells. The depth of the designed well in this area is 12 000 m (the vertical depth is 2 800 m), horizontal displacement is about 11 000 m), and the Prida of horizontal displacement and vertical depth is 3.93. The structure of the four opening wellbore is designed preliminarily. In the past, straight well drilling shows that the safety drilling fluid density window of the lower part of (Okobykaiskiy) and the (Daginskiy) formation of Dagi formation in this area is narrow (about 0.3 g/cm3), and the risk of leakage, collapse and card is high, while the problem of narrow safety density window of the corresponding well section of large displacement development well is becoming more and more prominent. In view of the shortcomings of the related research on expanding the narrow safety density window, especially the present situation limited to the expansion of the safety density window through the optimization of drilling fluid performance, around the drilling problem of large displacement wells with narrow safety density window, it is proposed that the narrow safety density window should be expanded in an all-round way by means of comprehensive mechanics and chemistry. First, the wellbore profile will be optimized and the stress state of the rock around the well should be improved from the wellbore trajectory design link. The extended safety density window is organically combined, and the influence of the main parameters of wellbore trajectory on the safety density window is analyzed. On this basis, taking into account the difficulty of wellbore trajectory control and construction friction, the wellbore trajectory is optimized, the collapse pressure is reduced, the formation fracture pressure is increased, and the safety density window is expanded in advance. It lays a good foundation for further improving the safety density window by optimizing drilling fluid performance, and finally creates favorable conditions for narrow safety density window safety and high efficiency drilling. The extended density window correlation technology has been successfully applied in the drilling design of large displacement wells in S block, which makes the safety density window of the target segment expand by 25% 鈮，
本文编号：2518640
[Abstract]:S block is located in the eastern sea area of Sakhalin Island in Russia and plans to be developed by sea-air and land mining technology in large displacement wells. The depth of the designed well in this area is 12 000 m (the vertical depth is 2 800 m), horizontal displacement is about 11 000 m), and the Prida of horizontal displacement and vertical depth is 3.93. The structure of the four opening wellbore is designed preliminarily. In the past, straight well drilling shows that the safety drilling fluid density window of the lower part of (Okobykaiskiy) and the (Daginskiy) formation of Dagi formation in this area is narrow (about 0.3 g/cm3), and the risk of leakage, collapse and card is high, while the problem of narrow safety density window of the corresponding well section of large displacement development well is becoming more and more prominent. In view of the shortcomings of the related research on expanding the narrow safety density window, especially the present situation limited to the expansion of the safety density window through the optimization of drilling fluid performance, around the drilling problem of large displacement wells with narrow safety density window, it is proposed that the narrow safety density window should be expanded in an all-round way by means of comprehensive mechanics and chemistry. First, the wellbore profile will be optimized and the stress state of the rock around the well should be improved from the wellbore trajectory design link. The extended safety density window is organically combined, and the influence of the main parameters of wellbore trajectory on the safety density window is analyzed. On this basis, taking into account the difficulty of wellbore trajectory control and construction friction, the wellbore trajectory is optimized, the collapse pressure is reduced, the formation fracture pressure is increased, and the safety density window is expanded in advance. It lays a good foundation for further improving the safety density window by optimizing drilling fluid performance, and finally creates favorable conditions for narrow safety density window safety and high efficiency drilling. The extended density window correlation technology has been successfully applied in the drilling design of large displacement wells in S block, which makes the safety density window of the target segment expand by 25% 鈮，
本文编号：2518640
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