Water-based Fracturing Fluid Damage Studies

Hydraulic pressure stimulation (Fracturing) of oil and gas well is the main method of stimulation. Accompany with the development of petroleum technology, fracturing is widely applied in oil field exploration and exploitation. Fracturing fluids play a very important role in the fracturing, which controls the success possibility of fracturing .The property of the fracturing fluids is better and better now. The type comes more too. But all types of fracturing fluids in fracturing have adsorption and retention of thickness agent in the stratum. This has not only reduced the utilization ratio of fracturing fluids but also injure the stratum .At present, many oilfields are testing the feasibility of using surfactant (CTAB) and high polymer (KTU) as thickness agent. The adsorption and retention of these two kinds of thickness agent is investigated in this paper.Firstly, this paper discussed the theory of adsorption from solution at solid/liquid interfaces and approached the mechanism and influencing factors of adsorption and retention. Then method of analysis the concentration of thickness agent was established in order to evaluate the adsorbance and retention. Based on these, we determined the adsorbance and retention quaniity of thickness agent on the condition of oil layer by the experiments of adsorption and retention. And the factors that influenced the adsorption and retention were studied. Finally, by the experiment of injure, we studied the degree of injure of the two kinds of thickness agent to the stratum.In the static adsorption experiment, when the two thickness agent (CATB, KTU) were adsorbed by the four adsorbing agents (GaoLin clay, Montmorillonite clay, Quartz sand and core sand), their adsorbance balanced time, and the relation between adsorbance and temperature/ concentration was determined .At last ,we worked out more than 20 curves and analyzed the characteristics of the curves.In the injuring experiment, According to "6.4 the method of determine the damaging rate of permeability " in SY/T5107 玊he evaluation criterion of performance of water-base fracturing fluid?, the damaging rate of permeability of three fracturing fluids (CATB,KTU and GUAR) were determined., and through that we evaluated their injury nature to stratum.In some extent, the experimental data and the conclusion from this paper will contribute on the fracturing which based on the two- thickness agent (CATB, KTU).Fracturing Fluids; Thickness Agent; Surfactant; Injuring;High Polymer; The Static Adsorption; The Damaging Rate of Permeability...