纤维水泥防漏实验研究

在孔隙型低压地层、渗漏型地层和诱导裂缝性地层固井时,水泥浆低返一直是影响固井质量的一大技术难题.室内实验评价了ZRF防漏增韧纤维水泥浆的常规固井施工性能和防漏性能,分析了其抗渗作用机理及堵漏机理.ZRF防漏增韧纤维材料具有一定辅助降失水功能,可提高水泥浆的沉降稳定性,使游离水降至很少,能够降低水泥石的渗透率和体积收缩率.评价结果表明,ZRF纤维防漏增韧水泥浆可以同时解决固井过程中的水泥浆漏失和改善水泥石脆性的技术难题,能封堵3 mm以下的裂缝性漏失和孔径小于0.45 mm的渗漏性漏失.

Experimental Study of Lost Circulation Protection of Fiber Cement

The porous formation,the absorbent formation or the induced formation had a common challenge in cementing quality as a result of lower upward height of cement.The mechanisms of impermeability and sealing were analyzed by evaluating the conventional cementing and sealing qualities of ZRF sealing and flexibility enhancing fiber cement in the laboratory.ZRF can assist filtrate reducing,enhance the sedimentary stability of slurry,decrease free water content greatly and reduce the permeability and volume shrinkage of cement stone.It is shown from the evaluation data that ZRF sealing and flexibility enhancing fiber cement can overcome challenges of lost circulation of slurry and brittleness of cement stone in cementing operation at the same time and can prevent fractured lost in which fracture diameter no more than 3mm and leakage of pore diameter no more than 0.45 mm.