A Study On Hydraulic And Thermodynamic Calculation For Oil-Gas-Water Three Phase Flow In Polymer Flooding

Hydraulic and thermodynamic calculation for oil-gas-water three phase flow in polymer flooding is an important part of the surface gathering and transportation system in oilfield.With the large scale application of polymer flooding technology for drilling oil,polymer flooding fluid out of wells whose thermo-hydraulic behaviors change significantly is with high viscosity and high degree of emulsification, compared with water flooding fluid out of wells.In this case, if directly using the typical hydraulic and thermal method to calculate the oil gas water mixed transportation pipeline, it will result in large deviations, so the quality of design will decline and the cost of production operation will increase.Thus, it has important theoretical and practical value to set up a hydraulic and thermodynamic method with required precision to calculate the oil gas water three phase flow pipeline. To solve this problem, this paper studies the hydraulic and thermodynamic calculation method of three-phase flow pipeline and draws the following research conclusions.1. The rheological characteristics of polymer flooding produced liquid are affected by temperature, moisture content and polymer concentration. The rheological measurement results show that under the low temperature environment contained polymers, polymer flooding produced liquid appears typical non-Newtonian flow structure due to irregular aggregation core and structure.2. A data acquisition system was designed to monitor and record the operating parameters of polymer flooding pipelines of Sanan Oilfield with high-accuracy. The system can collect the pressure and temperature of wellhead and metering room, liquid output, gas production and water content.3. Based on temperature drop of typical pipelines, the diameter specifications of different pipelines and the annual total heat transfer coefficients of different depth were modified and calculated. The average relative error of return oil temperature in metering room is within 5% by using the modified total heat transfer coefficient.4. To evaluate the hydraulic calculation results of typical Baker model, B-B model and L-M model, the polymer flooding mixed transportation pipelines of different oil gathering process in Sanan Oilfield was classified by different lift ways of wells. The three pressure drop models were modified by the unconstrained optimization model. Of the three models the modified Baker model is most accurate under different conditions and it is most suitable for the hydraulic calculation of polymer flooding produced liquid mixed transportation pipelines in Sanan Oilfield.5. The oil-gas-water mixing transportation hydraulic and thermal analysis software of polymer flooding was developed, which can realize pipeline drawing, thermodynamic calculation and hydraulic calculation of pipelines with friendly user interface and stable operation.