Analysis and control measures of suspended matters in Qikou 17-2 oilfield injection water

Suspended solid is the main control index of oilfield injection water, the exceeded suspended solids can easily block the leakage end face and seepage pores of injection wells, which cause water injection pressure increasing and injection rate declining, in a word, the effect of water injection is worse. Through the rock ore analysis to analyze the QK 17-2 oilfield water injection suspended solids, and put forward the solution to high suspended solid content and control measures of removing the blockage. Study shows that suspended solids content increases by 1.8 to 5.1 mg/L after the injection of fresh water and sewage water, the main reason is that fresh water and sewage water is not compatible, and the process is dirty. By the addition of 30mg/L antiscale 95% ATMP, the concentration of Ca²⁺, Mg²⁺ in the mixing water samples as well as the increase of suspended solids can be inhibited, installation of filter at the wellhead can further stabilize the quality of injection water. The main components of suspended solids in injection water are corrosion products of iron-sulfur compounds and formation mineral based on silicon and aluminum, which contain a small amount of calcium and magnesium-based carbonate, the main particle size is from 5μm to 15μm. By strengthening the acidification efforts of iron-sulfur compounds and increasing the dosage of hydrochloric acid pre-liquid, the blockages can be dissolved well and the water injection effect can be improved.