A Sduty On Distribution Characteristics Of Fluid And Temperature-Pressure Field In GuanTao Formation,Du84 Fault Block,Shu 1 Area,Liaohe Depression

As the effect of steam stimulation becomes weak and productivity declines shapely in Du 84 fault block,Shul area in Liaohe Depression after years of thermal recovery,pilot test of Steam Assisted Gravity Drainage has been carried on in Du 84 block since 2005 and obtains satisfactory results.But with the scale of test expanding and deepening,the phenomenon of steam overlap is significant,ascensional velocity of the steam gets fast and the situation of top water leaking downward becomes serious during medium-late stage of SAGD.Therefore,a systematic study and evaluation cn the distribution of the fluidsand temperature-pressure field have a great significance on the yield of the exploitation blocks and eventually enhanced oil recovery.On the basis of current exploitation status of heavy oil at home and abroad,this paper studies on geological conditions and subsurface fluidproperty of Du 84 block,Shul area,determines the oil-water interface based on coring wells and logging data,and identifies the distribution characteristics of fluid and the enrichment state of reservoir through drawing maps of oil reservoir profile and thickness.Guantao oil reservoir is a massive oil reservoir surrounded by edge water,top water and partly bottom water.The Guantao oil reservoir profile has an irregular round and ellipse shape,and gets thick in the center,of which the distribution is influenced little by formation lithology.There is no apparent cover rock and unified oil-water interface.The main reason that leads to oil reservoir plugging is the reservoir physical property reduced by variation of composition and structure of the rock.Based on the actual data of stimulation production wells,SAGD production wells and well temperature monitoring,150m is deemed as the secure boundary distance that locates wells to edge water.Through analyzing data of well temperature log and measured pressure of horizontal well and vertical well,currentreservoir temperature and pressure of portions of wells are obtained.The distribution characteristics of temperature field and pressure field of the whole area in recent years are studied by means of numerical simulation.Dynamic correlation analysis with horizontal well group concludes notable relation between daily oil production and reservoir temperature that daily oil production increases with higher temperature,and suggests that the pressure of steam cavity can be a criterion to the rationality of operating pressure of SAGD.Combined with the dynamic data of production wells and steam injection wells,the influence factors of Du 84 block of Guantao oil 1 reservoir are summarized.The steam cavity quantity is the key factor of production at the beginning of the SAGD,and the number of points of the steam injection well determines the number of steam cavity;with continuous injection of steam,production is determined by the growth of steam cavity and the main influence factor of the height of steam cavity is vertical heterogeneity of the reservoir.