PERFORMANCE OF LOW-CONCENTRATION GUAR GUM FRACTURING FLUID AND ITS APPLICATION TO QINGHAI OILFIELD

With thickener concentration ranging from 0. 18% to 0. 2%,a fracturing- fluid system of low- concentration guar gum has been developed. For this system,its thickener concentration is 40% ~ 50% lower than that of conventional guar gum fracturing fluid; and the cost can be reduced by 30% ~ 38%. In this study,some performances,excellent heat and shearing resistance,filtration property and quick gel breaking property,were evaluated. After using this system,not only core damage rate was just 22. 53% but also residue content was only 226. 3 mg / L,about half that of the conventional one. As a result,the damage of fracture conductivity caused by fracturing- fluid residue was reduced a lot. In 2012,this system was applied to 87 wells in Qinghai oilfield. The reduced cost was $ 4. 037 million. Especially after its application to 55 wells in Kunbei block,the stimulation ratio was 1. 08 times higher than that of fracturing wells in 2011. Therefore,the system has an obvious effect on reducing cost and increasing output.