支撑剂回流控制技术优化设计研究

Optimization design of controlling proppant flowback

焦国盈1 王嘉淮 游建国3 李 彭

重庆科技学院石油与天然气工程学院，重庆　401331 新疆油田公司采油工艺研究院，新疆　克拉玛依　834000 西南油气田分公司重庆气矿，重庆　400021 西南油气田分公司川东开发公司，重庆　400021

Department of Petroleum Engineering, Chongqing University of Science and Technology, Chongqing 401331, China Research Institute of Oil Production Technology, Xinjiang Oilfield Company, CNPC, Karamay 834000, China Chongqing Gas Field, Southwest Oil and Gas Field Company, CNPC, Chongqing 400021, China East Sichuan Development Company, Southwest Oil and Gas Field Company, CNPC,　Chongqing 400021, China

包覆支撑剂用来控制压裂井返排和生产期间的支撑剂回流。包覆支撑剂上的包覆层在地层条件下固化，将支撑剂胶在一起，阻止普通支撑剂或者地层砂向井筒的运移以达到控制支撑剂的目的。以最优化理论为基础，以压裂施工的净现值为目标函数，以砂量、砂比和施工排量为决策变量，建立了包覆支撑剂控制支撑剂回流优化设计模型。所建立的优化模型为多元非线性规划，采用优化方法——因素交替法求解。对每个单变量，采用均匀分批试验法求得最优值。依次对每个变量进行优选，就可求得局部最优解。该设计模型不依赖于裂缝几何尺寸模型与产能预测模型，可在保证支撑剂回流控制效果的基础上，从经济角度确定最优的包覆支撑剂量、包覆支撑剂段的砂比和包覆支撑剂段的施工排量等施工参数。采用该模型进行了实例计算，求出最优的包覆支撑剂加砂量为8　m3，最优砂比40%，最优施工排量为3　m3·min－１。计算结果表明，所建立的模型对指导现场施工有积极意义。

Resin-coated proppant has been used to control proppant production during fracturing fluid flowback and production. The mechanism of resin-coated proppant to control proppant flowback is that resin can cement proppant to form manual borehole wall which can prevent proppant grains or sand grains entering wellbore. This paper developed a optimization design model. The model is based on optimization theory. Its objective function is net present value of fracturing treamtment and decision variables are the volume of resin-coated proppant, resin-coated proppant congcentration and the treatment rate of resin-coated proppant stage. The established optimization model is by multivariate nonlinear programming and can be solved by factor alternating method. For every single variable, uniform partial experiment method is used to get the optimal value. Each variable will be optimized one by one and local optimal solution is obtained. The model presented is independent of fracture geometry model and production forecasting model. It can economically decide the optimal volume of resin-coated proppant, the optimal resin-coated proppant concentration and the treatment rate of resin-coated proppant stage on the base of guaranteeing the controlling effect of proppant flowback. Calculation is made with the establishment model, the optimal design is that the optimal coated sand content and support agent is 8m3, optimal sand is 40%, and the optimal delivery capacity is 3m3 / min. The results imply that the model presented has positive significance in instructing on-site construction.