胍胶稠化剂对低渗透砂岩气藏储层伤害的实验研究

Experimental Study on the Damage Caused by Thickener of Guanidine Gum of Low Permeability Sandstone Gas Reservoir

为了定量分析胍胶压裂液稠化剂分子对低渗透砂岩气藏储层的伤害情况,借助平行样比对方法,通过基质伤害实验和滤饼伤害实验,对目标储层10块(各5块)代表性岩心进行了研究。研究表明,在气相反排至50 PV时,稠化剂分子造成的伤害(堵塞伤害和滤饼伤害)是主要伤害因素(占总伤害的51.15%)。此外,堵塞伤害先是随着反排体积增加而增大,而后趋于稳定;滤饼伤害是不可逆不可恢复的伤害。并且,堵塞伤害与阈压喉道半径和有效喉道半径均值大小成线性正相关关系。

In order to quantitatively analyze the damage caused by thickener molecule of guanidine gum fractu-ring fluid of the low permeability sandstone gas reservoir, matrix damage experiment and filter cake damage experi-ment were conducted by using parallel samples comparison method on 10 representative cores（5 cores for each ex-periment）.Research shows that, the damage caused by thickener molecule of guanidine gum is the main damage factor （51.15%of the total damage） when gas reverse discharging to 50 PV.Besides, firstly, the blocking damage increases with the discharge volume increased, then tends to be stable, while, the filter cake damage is irreversible unrecoverable harm which doesn’ t change with the discharge volume.In addition, the blocking damage makes a positive linear correlation with threshold pressure throat radius and the mean size of effective throat radius.