松辽盆地基岩水平风险探井钻井优化设计与应用

Drilling optimization design and application of bedrock risk exploration horizontal wells in Songliao Basin

摘要:

为了保证松辽盆地首口基岩水平风险探井安全钻进、缩短施工周期，开展了井眼轨道、井身结构、钻井提速、复杂事故预防等优化设计，建立了不同开次套管抗内压强度计算方法，确定了有针对性的技术措施。通过地震剖面连线，确定了地质靶点，根据邻井实钻统计,121/2 in井眼设计采用1.5°螺杆，造斜率控制在(5°～7°)/30 m，设计了井眼轨道。基于气体与流体压缩系数的不同，研究了不同开次套管抗内压强度，发现生产套管井底是抗内压薄弱点，而其它开次套管抗内压薄弱点则是井口处。在井震结合的地质预测基础上，采用复合钻头、强化钻井参数等措施，比邻井钻速提高13.38%，采用复合堵漏技术，配套施工工艺，累计减少钻井液漏失247 m3。通过上述技术的研究与应用，隆平1井钻井周期同比隆探2井缩短21.16 d，从而为松辽盆地基岩风化壳勘探开发提供了技术支撑，为以后同类井的实施提供了依据。

Abstract:

In order to ensure safe drilling and shorten the drilling period of the first bedrock risk exploration horizontal well in Songliao Basin, optimum design of the borehole trajectory, casing program, drilling speed increase and prevention of complex incidents were carried out, calculation methods of internal compressive strength of casing at different well sections were established, and effective technical measures were determined. Geological targets were determined through the seismic profile. According to the statistics of actual drilling in the adjacent wells where 1.5° motor was used in the well drilling design, and the build rate was controlled at (5°～7°)/30m, the borehole trajectory was accordingly designed. Based on the difference in compressibility coefficients of gas and fluid, the compressive strength of casings with different spud was studied, and it was found that the bottom of production casing was the weak point, while for the other casing the weak point was at the wellhead. On the basis of geological prediction, the drilling speed was increased by 13.38% over adjacent wells by adopting the composite bit and strengthening drilling parameters, and circulation loss was reduced by 247m3 by using compound plugging technology and complete process. Through the research and application of the above technology, the drilling time of Well Longping1 was shortened by 21.16 days compared with the adjacent wells, which provides technical support for the exploration and development of bedrock weathered crust in Songliao Basin and provides a basis for the implementation of similar wells in the future.