Research On Gathering And Transportation Critical Conditions Of High-water-cut Thick Oil In Liaohe Oilfield

It is the later exploring stage in LiaoHe Oilfield that the water cut in the produced fluids increases continuously,and the energy consumption of the current gathering and transportation method which heats the oil by mixing with hot water is relatively high.To reduce the energy consumption and improve the efficiency of the gathering and transportation system,branched network of pipeline without heating is planned to be applied to the steam flooding block,while branched network of pipeline heating by hot water is adopted at the fireflood block to reduce the amount of back-admixing hot water and lower the energy consumption of the gathering and transportation system.The crude oil produced in the steam flooding and fireflood blocks of Liao He oilfield is thick oil with high viscosity and poor mobility,which makes the gathering process very difficult.So before the implementation of transformation programs,the feasibility should be checked in advance.That is,whether the gathering radius is larger than the actual transport distance and whether the gathering and transportation program is safe and reliable should be verified.The rheology of dewatered oil and water-oil emulsion produced in fireflood and steam flooding block is determined by experiment.The gathering and transportation model is built by software Pipephase used for the steady-state multiphase flow calculation,through which liquid viscosity is analyzed,pressure drop calculation model is determined,the new gathering processes is simulated,and the simulation is corrected by the actual production data.The water cut of fluids produced in the fireflood block is about 60%,approaching to the conversion point,so the apparent viscosity is relatively high,leading to that the fluids cannot transport without heating,and that blending with hot water is still needed after adopt the branched network of pipeline.The gathering radius of the transformation programs,especially the gathering distance of the remote wells,is researched,while the conveying temperature is optimized.The water cut and temperature of fluids produced in the steam flooding block are relatively high.The gathering radius of conditions(such as different liquids production,temperature,water cut,pipeline diameter,etc.)is determined.At the same time,the critical parameters such as temperature and liquids production of the gathering and transportation process without heating are researched.Finally,several reasonable suggestions for the oil production of fireflood and steam flooding blocks are proposed based on the experimental research and simulation results.