第40卷第2期
天然气勘探与开发
气用开发
斜率反转法在杭锦旗区块压裂施工中的应用
张宇张永春李月丽中国石化华北油气分公司工程技术研究院
摘要鄂尔多斯盆地北部杭锦旗区块的部分连续油管带底封压聚井在施工过程中存在砂堵间题，影响压裂施工周期和成功率。常规的砂堵分析方法在该区块实际施工过程中存在时效性差、指导不及时的问题。根据杭锦旗区块部分砂堵并的压裂施工曲线、压裂施工设计及实际施工参数分析，研究施工过程中泵注压力在支撑剂进入井筒和裂缝期间的变化规律，可预测地层或井简砂堵，及时指导现场压裂施工作业，结果表明：①泵注压力曲线可分为三个阶段，若前期压力下降，中期压力稳定，后期出现压力突升，偏离正常的变化斜率，表明可能产生砂堵，施工压力星示异常，应立即停止加砂采取猎施预防；①斜率反转法的砂堵特征在杭锦旗区块压裂施工中指示明显，据此现场采取措施，预防了2并次压聚中可能出现砂堵，效果较好：①应用表明斜率反转法方法简单，对现场施工快速预判砂堵，指导施工有一定参考价值，在加砂阶段的裂续净压力变化较小的工况中，方法准确性高。
关键词鄂尔多斯盘地杭锦旗区块水平井压裂
是连续油管作业
DOI: 10.12055/gaskk.issn.1673-3177.2017.02.013
现场施工
斜率反转法
预测砂堵
快速判断
Applicationofslopeinversionmethodtocoiledtubingfracturingwells
inHangjinqiblock
Zhang Yu, Zhang Yongchun, Li Yueli
(Petroleum Engineering Technology Research Institute, Sinopec North China Company, Zhengzhou, Henan 450006) China)
Abstract: In the Hangjinqi block in northern Ordos Basin, sand plug oceurred in some coiled tubing fracturing wells with bottom packer, impacting the fracturing operation period and success rate. When conventional sand plug analysis method is used for actual fracturing in this block, it cannot provide timely guidance, presenting poor time efficiency. In this paper, fracturing curve, fractur ing design and actual operation parameter of some sand-plugged wells in the Hangjinqi block were analyzed, and the change laws of pumping pressure in the process of proppant moving into wellbores and fractures were investigated. Accordingly sand plug in strata or wellbores could be predicted to provide timely guidance for field fracturing. It is indicated that pumping pressure curve can be divided into three stages, i.e., pressure decline in the early stage, stable pressure in the middle stage and abrupt pressure increasing in the late stage. If the change slope is deviated from the normal one, sand plug may happen. Once abnormal fracturing pressure occurs, it is nec-essary to stop sand pumping immediately and take some measures. When the slope inversion method was used for fracturing operation in the block, the characteristic of sand plug was presented obviously. Accordingly, some measures were taken, and possible sand plug in two well times' fracturing were effectively prevented. It is demonstrated that the slope inversion method is simple and can be used as the reference for fracturing operation owing to its quick prediction on sand plug. Its accuracy is high when net fracture pressure var-ies in the small range in the process of sand pumping.
Keywords: Ordos Basin; Hangjinqi block; Horizontal well fracturing; Coiled tubing operation; Field operation; Slope inversion meth-od; Sand plug prediction; Quick prediction
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引言
压裂中常用的砂堵分析方法有净压力拟合法和
施工压力双对数曲线法，这两种方法在预测砂堵指导现场施工中存在时效性问题。
净压力拟合法是将水力压裂施工时监测到的井底缝口压力与三维压裂软件模拟计算的缝口压力进行拟合"。通过分析净压力变化，发现脱砂迹象来判断砂堵，判断依据是观察净压力与时间的双对数曲线斜率是否趋于1围。净压力预测砂堵在现场应用
第一作者：张宇，1987年生，助理工程师，硕士；从事储层改造方面的研究工作。地址：（450006）河南省郑州市陇海西路199 号中国石化华北油气分公司工程技术研究院。E-mail：fxs12tank@163.com
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