东方1-1气田浅层大位移水平井钻井技术

The extended reach horizontal well drilling technology suitable for shallow layers in Dongfang 1-1 Gasfield

田宗强 鹿传世 王成龙 韩成

TIAN Zongqiang LU Chuanshi WANG Chenglong HAN Cheng

中海石油（中国）有限公司湛江分公司

Zhanjiang Branch of CNOOC, Zhanjiang 524057, Guangdong, China

东方1-1气田浅部储层已进入开发中后期，受海上平台空间、井槽数量等条件限制，现多采用“外挂井槽+大位移井”或“老井侧钻+大位移井”的模式挖潜平台周边剩余油气。该区域浅部地层疏松，同时受群桩效应影响，表层桩管鞋易窜漏，井眼轨迹控制难度大，并且该气田储层压力衰竭，在前期的钻井作业过程中卡钻、卡套管、井漏等井下复杂情况频发，钻井时效低于70%。针对以上问题，在表层隔水管选型、提高钻井液封堵性及润滑性、精细控制井眼轨迹等方面进行了技术攻关，于2016年在东方1-1气田X4平台4口大位移水平井上进行了应用并进一步完善，最终形成一套适用于该气田的浅层大位移水平井钻井技术。2017年底将该技术应用于东方1-1气田X1平台的1口水平位移4 107 m、水垂比3.119的水平井，整个钻进过程未发生漏失及井下复杂情况，钻井时效提高至99%，该研究为东方1-1气田后续类似井施工提供了技术参考。

The shallow reservoirs in Dongfang 1-1 Gasfield are in the middle and late stage of development. Due to the restriction of offshore platform space and well slot quantity, the potential tapping of remaining oil and gas in the periphery of the platform is mostly carried out in the mode of "external additional well slot+extended reach well" or "old well sidetracking+extended reach well". The shallow formations in this area are unconsolidated, and together with the effect of pile group, channeling and leakage tend to happen at the surface pile casing shoe and well trajectory control is difficult. Besides, the reservoir pressure in this Gasfield is depleted. As a result, the complicated downhole accidents happen frequently in the process of early drilling, such as pipe sticking, casing sticking and lost circulation, and the drilling time efficiency is lower than 70%. A series of technological researches were carried out in terms of surface riser type selection, drilling fluid plugging and lubricating performance improvement and fine well trajectory control to solve these problems. In 2016, the research results were applied in 4 extended reach horizontal wells on X4 platform in Dongfang 1-1 Gasfield. Thus, a set of extended reach horizontal well drilling technology suitable for the shallow layers in Dongfang 1-1 Gasfield were ultimately developed after further improvement. In 2017, this technology was applied in one horizontal well with horizontal displacement of 4 107 m and horizontal-to-vertical ratio of 3.119 on X1 platform in Dongfang 1-1 Gasfield. No leakage or complex downhole situations occurred in the whole process of drilling and the drilling time efficiency was increased to 99%. The research results provide the technical reference for the construction of similar wells in Dongfang 1-1 Gasfield.

10.13639/j.odpt.2018.02.002