页岩气地质工程一体化导向钻井技术

Integrated Steering Drilling Technology for Geology Engineering of Shale Gas

为最大限度地挖掘页岩储层潜力,提高水平井勘探开发效果,研究应用了页岩气地质工程一体化导向钻井技术,包括:在深化页岩储层认识和准确预测"甜点"的基础上,建立了精细三维地质模型;根据三维地质模型提取的地层参数进行井眼轨道优化设计;采用储层预测技术,落实目的层微构造变化,从而为水平段井眼轨迹预测提供地质依据;采用地质目标跟踪及轨迹调整技术,准确预测井底钻头位置,估算真实地层倾角并实时修正地质模型,确保井眼在储层中合理位置延伸。地质工程一体化技术在四川盆地NH2-4井进行了应用,确定水平段位置距优质页岩底界35.00m,校正真实地层倾角为6.48°,实时修正地质模型并调整井眼轨道设计参数,实现优质储层钻遇率94.5%。研究结果表明,页岩气地质工程一体化导向钻井技术,为页岩气开发提供了实用可行的集成技术。

In order to best tap the potential of shale reservoirs and optimize the placement of horizontal wells during exploration and development,an integrated steering drilling technology was researched and developed in this paper.First,after an in-depth understanding of the shale reservoir was achieved,a highresolution 3Dfine geologic model was developed that could accurately predict＂sweet spots＂.Second,optimization design was conducted on the well trajectory on the basis of the formation parameters extracted from the 3Dgeologic model.Third,microstructure change of target zones was ascertained by using reservoir prediction technologies,so as to provide the geologic basis for the well trajectory prediction.Fourth,the position of the bit was predicted in the hole accurately by means of geological target tracking and trajectory adjustment technologies.And finally,real-time modification was conducted on the geologic model by estimating the real formation dip,so that the well trajectory could be extended reasonably in the reservoirs.The technique was applied in Well NH2-4during the drilling of its horizontal section.And based on the technique,it was 35.00 mfrom the horizontal section to bottom boundary of high-quality shale,and the corrected formation dip was 6.48°.The geological model was real-time modified and the trajectory parameters were adjusted for time,so high quality reservoir drilling rate achieved 94.5%.It is shown that the integrated steering drilling technology for geologic engineering provided apractical and feasible integration technology for the development of shale gas.