ChangQing Oilfield Wastewater Reinjection Study Engineering

Oil Production Plant of Changqing Oilfield under a joint station located in Jingbian County, the sector is characterized by low-oil plant, low permeability high re-injection, the oil plant oil wastewater with high oil content, suspended solids and high sulphide content and more volatile large, bacteria (including sulfate-reducing bacteria and saprophytic bacteria) were higher Ca2+ions into the dirt and Mg2+content and high corrosion fouling resistance. In order to increase oil production, increase the rate of water reinjection and protect the environment, the paper by adjusting the pH value, preferably sulfur removal agent type and dosage, and organic flocculants inorganic coagulant type and dosing techniques, flocculation treatment of oily wastewater, and to study the treated water and formation water compatibility, because the water can not reach back to the injection of water quality indicators, coupled with corrosion and fouling problems highlighted, oil production has brought to the injection pressure increases, a series of problems such as corrosion of pipelines, low permeability oilfield water injection problem is particularly serious harm. Oil recovery plant wastewater weakly acidic pH of5.0to6.5, suspended solids content of100～120mg/L, oil content (70～100mg/L), total iron content (16.3～36.0mg/L), the bacterial content (sulfate-reducing bacteria105～106/mL; saprophytes102～103/mL) high, and the indicators are far beyond the Changqing oil field injection water quality standards.In this paper, laboratory data and field reinjection process rational analysis, the use of laboratory chemical methods, a detailed analysis of a block of northern Shaanxi Changqing oilfield waterflood recovery back to the nature and characteristics of the composition studied antifouling agents, preservatives, the use of water treatment chemicals modified the effect of oily wastewater reinjection process and its influencing factors, screened applicable recovery water injection drug use put, finally, through the advantages and disadvantages of oily wastewater treatment process and scope of studies to determine the suitable recovery injection water treatment process consisting of the nature features are:scale sterilizationâ†'eutralization (pH adjusted to7.5至8.0)â†'iron oxide corrosionâ†'flocculation filtration, the study of injection water reinjection recovery process and pharmaceutical complex in-depth study and determine the selection of HDS-08as fungicides, AD43-3-b as scale inhibitors, pH, optimum range of7.5to8.0, H2O2addition to iron oxide, XN-90is an inorganic flocculant, KS-1inhibitor available for the best conditions for reinjection conclusions. The results from the study shows that the use of sedimentation, coagulation, filtration post-treatment process steps can be taken out so that the total iron content in sewage, oil content, suspended solids, bacteria content effectively reduced, so that the treated produced water to reach Changqing Oilfield Company oilfield produced water reinjection standards, research achieved more satisfactory results, after reaching sewage water standards.