致密砂岩储层水力加砂支撑裂缝导流能力

裂缝的导流能力对于水力加砂压裂效果影响很大,分析裂缝导流能力影响因素、研究如何增加裂缝导流能力,对于提高压裂增产效果具有重要意义。针对长庆油田安83区块致密砂岩储层的特点,使用Meyer软件对裂缝的各项参数进行模拟预测,考察了支撑剂类型、粒径、铺砂浓度、嵌入以及压裂液残渣对砂岩储层裂缝导流能力的影响,并进行了增产效果预测。结果表明:陶粒的导流能力远大于石英砂和树脂砂;低闭合压力下,粒径越大,导流能力越高,随着闭合压力的增大,大粒径支撑剂导流能力下降幅度较大;不同粒径组合支撑剂的导流能力下降幅度相比较于单一粒径支撑剂要平缓得多;铺砂浓度越高,裂缝导流能力越高;当闭合压力为70 MPa时,支撑剂的嵌入可使导流能力下降30.1%;压裂液残渣可使不同粒径支撑剂的裂缝导流能力出现不同程度的下降;增产倍数与裂缝导流能力成正比,当陶粒筛选目数10/20、20/40和40/60组合且比例为1∶3∶1时,增产倍数最大。在低渗透储层压裂现场应用,增产效果较好。

CONDUCTIVITY OF THE HYDRAULIC SAND-ADDED FRACTURES IN THE TIGHT SANDSTONE RESERVOIR

The flow conductivity of the fracture has great influence on the hydraulic fracturing effects,therefore analyzing the influencing factors of the fracture conductivity and studying how to increase the conductivity possess important significance in improving the effects of increasing the fracturing production.In the light of the characteristics of the tight sandstone reservoir of Changqing-Oilfield Block An 83,with the help of Meyer Software,each parameter of the cracks was simulated and predicted,the influences of the proppant type,particle size,sand concentration,embedding and fracturing fluid residue on the fracture conductivity of the sandstone reservoirs were investigated,and moreover the effects of enhancing the production were forecast.The results show that the flow conductivity of the ceramsite or haydite is much greater than that of the quartz sand and resin sand;the flow conductivity grows with the rise of the particle size under the low closure pressure;as the closure pressure increases,the flow conductivity of the proppant with large particle size decreases sharply;the conductivity of the combined different particle sizes of the proppant decreased more gently compared with the single diameter proppant;the larger the sand concentration is,the higher the fracture conductivity will be;when the closure pressure is 70 MPa,the embedment of the proppant can make the flow capacity decreased by 30.1％;the fracturing fluid residue can make the fracture conductivity of different-size proppants decreased to a different extent;the produced multiple is proportional to the flow conductivity of the fractures;for 10/20 mesh,20/40 mesh,40/60 mesh haydite combination,when the ratio is 1 ∶ 3 ∶ 1,the enhanced production multiple is the largest.Much better enhancement effects have achieved in the field application of the fracturing stimulation in the low permeability reservoir.