Analysis of Scaling Composition and Selection of Scale Inhibitor for the Flowback Fracturing Fluid in Liaohe Oilfield

During the hydraulic fracturing process in Liaohe Oilfield, when the mineralization of formation water and fracturing fluid allocation water is high, the scaling problem in the post-fracturing pore and proppant pack zone is very serious, which seriously affects the permeability and production capacity of oil and gas wells. In response to this situation, Liaohe Oilfield has already put a certain concentration of phosphate-based inorganic scale inhibitor on site, but the effect is not good, and at present, the scaling composition in the return fracturing fluid is not clear, so it is not possible to formulate a reasonable scaling inhibition program. In order to solve these problems, this paper firstly adopts the inductively coupled plasma technology to analyze the water quality and the X-ray diffractometer to detect the scale samples, and then analyze the scale composition. In addition, the performance of various scale inhibitors was evaluated by calcium carbonate deposition method, and a green polymer-based scale inhibitor CG2–2 was screened and simulated for field application and concentration preference experiments. The results show that the main type of scale in the fracturing fluid of Liaohe Oilfield is calcium carbonate, and the scale inhibition rate of CG2–2 is as high as 98.08%, with the optimal concentration of 60 mg/L. This study not only provides a feasible anti-scaling technical solution for Liaohe Oilfield, but also provides a theoretical basis and technical reference for anti-scaling of hydraulic fracturing in the same kind of high-mineralization oilfields.