A study of oil-base fracturing fluid

A new oil base fracturing fluid has been studied and reported, which can be used for developing of reservoirs under the conditions of low pressure, low permeability and water sensitivity. According to the component of crude oil, a thickener synthesized, which can be reacted with crude oil and be mixed into thickened oil. Through a cross linking reaction, a gel system is formed. The viscosity of gel can be controlled by the concentrations of thickener and cross linker. Crude oil is used as a substitute of diesel and kerosene in this oil base fracturing fluid, so the cost of fracturing fluid is decreased sharply. At the same time, thermo stability and shearing strength are increased. The cross linking time can be controlled in 2 hours. After gel breaking reaction, the viscosity of fracturing fluid is decreased, which is correspond to that of crude oil. The new oil base fracturing fluid can be used economically and easily in some low permeability oil fields. A pilot test is conducted successfully in Qinghai Huatugou oil field, Qinghai Province, northwest China.