酸化技术是油水井增产增注的重要措施,但由于酸化措施井工况复杂,确定施工参数困难,所以建立注水井酸化模型,优化参数十分必要.使用灰色关联分析方法找到各施工参数与注水井日增注量的关联程度,建立BP神经网络程序,依靠现有数据对其进行训练,依次对人为可控参数预测,找到最佳施工参数组合.以单井为例进行参数预测,指导现场施工.结果表明,将数学方法和注水井酸化施工工艺相结合,建立模型预测参数,能显著提高注水井增注效果.

In recent years, the measure of fracturing fluid blending was adopted prior to operation. The traditional form of fluid blending not only has the problem of long operation cycle and high strength of fluid blending and so on, but also has difficult disposal of flowback waste fluid and reservoir damage. For avoiding the disadvantages of traditional fluid blending, the online preparation for polymer fracturing fluid (OPPFF) is developed to replace the traditional melon gum system for preparing fracturing fluid continuously on-line. Laboratory e-valuation results show that the viscosity of OPPFF is above 60 mPa.s after 90min shearing at 120 degrees C and 170 s(-1), which could meet the requirements of conventional fracturing. Low molecular polymer emulsion, multifunction additive and ammonium persulfate are pumping into sand blender by metering pump, then mixed with water and propping agent to finish the fluid blending process with 50% sand ratio. It has strengths such as easy preparation, less waste of materials, low reservoir damage and no pollution, and obtains a high efficient and environment protected fracturing operation. The application results are desirable and it has prosperous future for dissemination.

本文通过对常规煤岩裂缝扩展监测方法优缺点进行分析,从煤岩无损化角度出发,提出了应用CT扫描技术对煤岩裂缝扩展进行分析的新方法.试验结果表明:天然裂缝和割理等弱面对水力裂缝扩展有重要影响;水力裂缝在穿透弱面扩展过程时压力曲线存在明显的憋压,产生沿割理方向的水平缝,沟通割理过程中压力曲线上下波动明显.

暂堵转向压裂是提高初次压裂压后短期内高含水油井产量和采收率最有效的增产措施之一.在分析初次压裂裂缝诱导应力场和油井生产诱导应力场基础之上,提出了转向压裂裂缝扩展轨迹预测方法.对比分析轨迹预测方法预测结果和转向压裂微地震监测结果发现:受初次压裂裂缝诱导应力大小和油井生产时间的限制,转向压裂裂缝扩展轨迹并不沿垂直于初次压裂裂缝方向,而是以与初次压裂裂缝成一定夹角的方向延伸;较大的初始地应力差将使转向压裂裂缝在回到与初次压裂裂缝方向相平行方位的垂向穿透距离受限.该研究成果对暂堵转向压裂施工规模设计及压后效果分析具有一定指导意义.

High pressure oil and gas reservoir hydraulic fracturing is a difficult problem in Blocks J29 and C71 in Huabei oilfield.Aiming at this,a high density fracturing fluid system was developed by choosing sodium bromide and sodium nitrate as mixed weighting agent.Research showed that the density of this fracturing fluid can adjust between 1.20~1.55 g/cm3;And its viscosity is more than 100 mPa·s after 90 minites shearing under the conditions of temperature 160 ℃ and shear rate 170 s 1.4 wells field application in Huabei oilfield has showed that,compared with common fracturing fluid,the construction output increases 1.0~1.5 m3/min with the high density fluid,and proppant concentration climbs 5~16 percentage point with the decresing of well head pressure in 7~15 MPa.The fracturing effect significantly improves compared with wells in adjacent block.