田菁胶残渣及其对压裂井产能的影响

EFFECT OF SESBANIA GEL ON FRACTURING WELL PRODUCTIVITY

油层水力压裂施工中常用的水基冻胶压裂液在破胶后一般都有一定量的残渣.这种残渣一方面可堵塞地层和支撑裂缝孔隙,另一方面可形成滤饼,降低滤液侵入地层深度,减轻地层伤害.本文用田菁压裂液研究了其残渣含量对不同渗透率人造岩心伤害程度的影响,并在模拟压裂液滤失条件下测定不同残渣含量的压裂液对填砂裂缝的伤害程度.用数值模拟方法研究了地层及裂缝的伤害程度及压裂液侵入地层的深度对压裂井产能的综合影响.结果表明.当综合考虑压裂井地层和裂缝伤害程度预测出的产能.较接近实际产能.并提出了根据地层渗透率选择压裂液残渣含量的参考方法.

The residue in water-based fracturing fluid after break-down has opposite effects on fracturing treatment. It can damage formation and proppant pack by blocking pores: On the other hand, the residue can alleviate formation damage by forming filter cake to decrease the invasion depth of fracturing fluid into the formation. This paper studies the degree of formation damage caused by sesbania gel fracturing fluid under conditions of different residue contents and formation permeability by using artificial cores. The degree of fracture conductivity damage was determined by the use of fracturing fluids with different residue contents under the condition of simulated fluid loss. The comprehensive influence of invasion depth and formation and fracture damage on well productivity was studied. The result indicates that the productivity predicted by considering the influence of formation and fracture damage, is close to real productivity. A method for selecting residue contents in fracturing fluid with regard to pay zone permeability is proposed.