苏北盆地页岩油井钻井取心复杂及对策研究

Complexity and Treatment of Shale Oil Well Drilling Coring in Subei Basin

针对苏北盆地阜宁组页岩油“烃源岩”储层钻井取心过程中存在的引心困难、堵心、掉心、钻头泥包、岩心爪变形导致岩心收获率低等复杂情况,根据沉积岩XRD定量分析和黏土矿物含量化验结果,在苏北盆地阜宁组泥页岩120井次、470回次取心实践的基础上,总结了苏北盆地地层特点及取心技术难点,以及导致苏北盆地泥页岩钻井取心复杂情况的各类因素,开展取心工具的比选与研制,形成复杂井段钻井取心技术措施,并在苏北工区开展应用12口井,取心复杂故障率为0,其中重点探井QY-1井连续钻井取心26回次,取心进尺404.22 m,平均机械钻速6.18 m/h,取心收获率99.22%,刷新2021年度中石化连续取心最长纪录。针对苏北盆地页岩油井钻井取心过程中复杂情况的处理对策,解决了该区域钻井取心的复杂问题,提高了取心成功率和机械钻速,具有推广应用的前景。

In view of the low coring recovery resulted from such complicated conditions as difficulty in coring,core blocking,core loss,bit balling and core clawing deformation during the drilling process of“source rock”shale reservoir of Funing Formation in Subei basin,according to the results of XRD quantitative analysis and clay mineral analysis of sedimentary rocks and based on 120 wells in Subei basin and 470 times of coring practice in Funing mud and shale formation,summarized the formation characteristics and technical difficulties of coring in Subei Basin,as well as various factors leading to the complicated situation,and carried out the comparison and development of coring tools,formed corresponding countermeasures and technical measures for dealing with the complex situation.12 Wells of the subsequent application,the coring complexity failure rate is 0,among which the key exploration well QY-1 had been continuously performed coring for 26 times,with a coring footage of 404.22 m,an average ROP of 6.18 m/h,and a coring recovery percentage of 99.22%,which refresh the longest continuous coring record of Sinopec in 2021.In the process of shale oil and gas well coring,the complex problems of drilling coring in this area are solved on site,the success rate of coring and the ROP are improved,which has the prospect of practical popularization and application.