High Molecular Weight Surfactants Clean Fracturing Fluid

Hydraulic fracturing is an effective measure of renewing reservoir and important to enhance oil-gas well production and water well injection. Fracturing fluid is the key factor in the fracture treatments. There are many kinds of frac- fluids. At the present time, water-based fracturing fluids are popular because of low costs and steady performance, which has the proportion of 90%. However it performs badly in the high temperature and do damage to the formations which confines its development. And the newly developed clean-fracturing fluid has small damage to the formation, but it cost too high to apply it widely. These conditions compelled us to excogitate the new fracturing fluid, which has the properties of high temperature resistance, low cost and low damage.Through analyzing the situation of fracturing fluids and the character of the polymer surfactant needed by the oil field, we have the idea of high temperature resistance clean frac-fluids consists of polymer surfactant and its additives. We analysis the characters of this kind of clean frac-fluid and found it satisfied with the requirements of the fracture treatments.According to known knowledge we design the polymer surfactant. Results prove that it has the performance traits of surfactants and could crosslink at certain concentration. So this gets to our designing requirements completely. Analyze the polymer surfactants properties of resisting temperature and salt and shearing. And the feasibility of acting as resisting high temperature and low damage fracturing fluid compounded with its additives is also considered. Experiments show that: the compound system of polymer surfactants and additive of YZ-1 has fine tackify character, notable temperature resistance, certain salt tackify ,shear-thinning property. It can be used in the frac-treaments.Measuring other characters of the compound system by the standard performance of water-based fracturing fluid. Results prove that it can satisfy with the requirement of low leak-off and low damage in the treatments. Temperature-resist of the compound system can reach to 130℃ It break soon and completely without residua. It can carry proppant at low viscosity. The damage to the core matrix due to the broken frac-fluids is lower than the viscoelasticity surfactant frac-fluids do. That is to say, using the compound system as fracturing fluid can notably resist high temperature and it is clean frac-fluid too.So, we get the requirments of frac-treatments by molecule design, theory analysis andexperiment prove. The high temperature resistance and low damage clean fracturing fluid compounded by polymer surfactant and its additive has been successfully excogitated.