Experimental Study On Compound Thermal Recovery Of Heavy Oil And Optimization Of Production Parameters In P691 Block

P691 heavy oil block is located in the northeast of Che Pai uplift in Xinjiang,and is one of the main oil producing areas of CF oilfield.As an important oil resource,complex thermal recovery method is an effective method for developing heavy oil.Therefore,for the P691 heavy oil block,first of all,the geological characteristics are analyzed,and the geological parameters are determined;Through the block oil test data,determine the development block and development mode;Based on the laboratory experiments of heavy oil recovery in heavy oil samples in P691 block,the effects of various factors on thermal recovery are concluded;Through the research of economic and technical boundaries,the production parameters of thermal recovery in vertical and horizontal wells are optimized.Finally,the production scheme of P691 heavy oil block is given,and the indexes are predicted.Obtain the following knowledge:(1)Production cycle is not complete,the peak oil production test wells with certain amount and the initial capacity,but the wellhead temperature is low,fast production decline,the production time is short;the effective thickness of thin oil region HDNS development system can realize the effective use,and regional big effective thickness by VDNS can achieve effective use;effective thickness,heterogeneity strong,the bottom edge of the water,and the testing time is short,the 694 row of blocks currently being used.(2)Through indoor heavy oil thermal recovery experiment:composite oil soluble viscosity reducer greatly reduce the viscosity of heavy oil,heavy oil yield value and starting pressure of steam injection,to ensure uniform diffusion of temperature field during the process of steam injection;nitrogen significantly increased shallow heavy oil reservoir in the process of producing differential pressure,prolong the production period and increase the production cycle the volume of liquid;nitrogen can reduce the thermal conductivity of reservoir rock in the reservoir,reduce the heat loss of thin heavy oil reservoir along the upper cover layer,improve the utilization rate of steam heat;nitrogen and oil soluble viscosity reducer with steam combination can greatly improve the displacement efficiency and sweep efficiency of water flooding.(3)The following conclusions are drawn by study on economic boundaries and the boundaries of technology development of hot Nii:determine the different oil prices to economic limit yield and economic limit of oil and gas ratio;numerical P691 well established vertical well and horizontal well model,and the oil production curve and water content curves were fitted respectively;the horizontal and vertical wells region of well,well spacing,row spacing,length of gas injection wells,nitrogen injection volume and injection cycle cycle viscosityreducer amount,steam injection intensity,flooding time,gas injection rate,injection production ratio and thickness of wells were optimized.(4)The development plan to deploy a total of 35 horizontal wells and vertical wells 36,steam stimulation Scheme Simulation Production 13 years cumulative production of 775 thousand tons,the recovery level of 18.2%;steam + steam flooding scheme simulation production for 15 years,the cumulative oil production of 1 million 331 thousand tons,the recovery level of 31.2%.