玛北地区二叠系风城组页岩油钻井优化实践与下步建议

Drilling Optimization Practice and Suggestions of Permian Fengcheng Formation Shale Oil in Mabei Area

近年来,玛湖风城组页岩油勘探取得重大突破,落实3.05×10^(8)t储量规模,成为玛湖油田上产500×10^(4)t的主要战略接替层系,玛湖页岩油在压力系统、埋深、岩性等方面与其他区块页岩油存在巨大差异,现有技术适用性差,单井投资高,难以支撑效益开发建产。为了进一步降低玛湖风城组开发成本,在玛51X井区进行钻井优化先导试验攻关,通过提高生产组织衔接、基于机械比能(MSE)科学优选钻井参数、科学井眼清洁措施、优选提速工具与优化钻头等一系列钻井优化实践,配套形成一套水平井钻井优化技术。通过攻关试验,大斜度穿层井钻井周期由78.21 d减少至59.60 d,水平段趟钻最高进尺由296 m提升至460 m,极大的降低了钻井成本。但目前针对难钻高阻地层钻进仍需进一步优化,钻头复合片耐磨及抗崩性能需要提升,配套大扭矩螺杆实现高效钻进。

In recent years,the shale oil exploration of Fengcheng Formation in Mahu has made a major breakthrough,and the reserves of 305 million tons have been implemented,which has become the main strategic replacement layer producing 5 million tons in Mahu oilfield.There are huge differences between Mahu shale oil and other block shale oil in the aspects of pressure system,burial depth,lithology,etc.,and the applicability of existing technology is poor,and the investment of single well is high,which is difficult to support the cost-effective development and production.In order to further reduce the development cost of Mahu Fengcheng Formation,the pilot test of drilling optimization was carried out in the Ma 51X well area,and a set of horizontal well drilling optimization technologies was formed through a series of drilling optimization practices,such as improving production organization connection,scientific optimization of drilling parameters based on MSE mechanical specific energy,scientific borehole cleaning measures,optimization of acceleration tools and optimization of drill bit.Through the key test,the drilling cycle of the highly inclined penetration well is reduced from 78.21 days to 59.6 days,and the maximum penetration of the horizontal section is increased from 296 m to 460 m,which greatly reduces the drilling cost.However,at present,it is still necessary to further optimize the drilling for the difficult and high resistance formation,the wear resistance and collapse resistance of the drill bit composite sheet need to be improved,and the large torque screw is used to achieve efficient drilling.