Research and application of new carboxymethyl fracture fluid

Rheological behavior and damage characteristics of the new carboxymethyl fracture fluid under 70 ℃ are evaluated in this paper, according to SY/T 5107-2005 Performance Evaluation of Water-based Fracturing Fluid. Results show so-called two higher and three lower characteristics of higher elasticity, higher sand carrying ability, and lower concentration of thickener, lower viscosity of based fluid, lower damage. These properties are obviously better than those of usually used hydroxypropyl guar gum fracture fluids. Therefore, the new fracture fluid is suitable to fracturing geological features of Baibao district in Changqing Oilfield. Through the optimal design of Yuan 27-15 well and Yuan 30-15 well, the new carboxymethyl fracture fluid was used for fracturing for the first time in China. The test oil output of the wells is 24 t/d and 15.6t/d respectively after fracturing, which is 2 to 3 times higher than the average output of the district. It proves that the new carboxymethyl fracture fluid can be better used for ultra low permeability reservoirs.