油井压裂纤维控砂工艺技术研究与应用

Research on fiber composite sand control technique for oil well fracturing and its application

对压裂井加快排液速度和控制支撑剂回流返吐是一对矛盾,排液速度太快可能超过临界出砂流速,导致支撑剂回流,缝口处的导流能力大大降低;排液速度太低又会导致排液时间增加,降低返排率。为解决这一矛盾,研究了纤维控砂工艺技术。阐述了纤维复合控砂技术原理,介绍了砂岩地层压裂井返排数学模型的建立及功能,特种纤维的制备及其性能评价,得出特种纤维的优越性和可行性。在优化压裂工艺的基础上,对W15-4等三口井实施了压后强制返排工艺,对M20-5井实施了纤维固结防砂工艺,取得很好的应用效果,得出纤维控砂工艺是有效解决压裂井加快排液速度和控制支撑剂回流返吐这一矛盾的有效手段。

Promoting liquid drainage velocity and controlling proppant backflow is a couple of intensification in fracturing treatment.High drainage velocity exceeding critical sand producing velocity may cause proppant backflow to reduce greatly the fracture conductivity.But low drainage velocity may cause flowing time to increase and efficiency to reduce.In order to solve this contradiction,the technique of fiber composite sand control is introduced and a mathematical model is established to describe postfrac flowback of sand formation.It is proved that the special fiber is superior and feasible to prevent proppant backflow by performance evaluating.Based on the optimized fracturing technology,the postfrac compulsory flowing back of fracturing liquid was implemented in 3 wells such as well W15-4 and fiber-resin coated sand control was applied in well M20-5.A remarkable effect has been obtained and it is proved that the technique of fiber complex sand control is a good method to solve the contradiction between the quick flowing back of fracturing liquid and proppant backflow control.