Technical Study On Improving The Development Effect Of Horizontal Wells In Heavy Oil Reservoirs In Well Z18

After 2010-2014 years of large-scale production capacity construction,the total well number,the number of startup well,the level of steam injection and the oil production level are increasing continuously of Jurassic extra heavy oil reservoir in Z18 well area of Fengcheng oilfield.And in October 2013,the oil production level reached the highest value.Whereafter,because of the capacity construction scale gradually reduced,the oil reservoir quality gradually became worse,and the old wells decreased gradually.As a result,the production level of oil is decreasing gradually.Meanwhile,the problems like high viscosity of crude oil,large sand production and uneven utilization of horizontal section are also faced,which seriously affects the development effect.By analyzing and evaluating the development effect of horizontal Wells in well Z18 and pointing out the existing problems,targeted measures are optimized to improve the development effect of horizontal Wells and realize stable production and increased production.The grey relational analysis method is used to evaluate and analyze the main factors that affect the development effect of horizontal Wells.The DOE method was introduced to quantitatively analyze the effects of four influencing factors,including permeability,crude oil viscosity,reservoir thickness,and horizontal section length,on the production rate and oil vapor ratio of horizontal Wells.In three typical injection-production parameters of well group,on the basis of single factor analysis of DOE software and numerical simulation for different injection-production parameters combination of multiple factors analysis,the stage of different combined parameters analyzes parameters regression and significant cumulative oil production,that only an increase in cycle at the same time the amount of steam injection liquid withdrawal rate to increase oil production.Through analysis,research and evaluation,the optimization of steam injection method,steam injection parameters and process measures in horizontal well of Z18 is realized.For the horizontal well group with abundant difficult recovery remaining heavy oil between horizontal Wells,the effect of increasing production can be achieved by adopting the steam injection method of vertical well steam injection.For the horizontal well group with long throughput production time,good condition of central injection-steam Wells,obvious steam channeling and well thermal connection established between Wells,the production effect of one injection-multiple production is good.After using the tandem pump to produce 2-3rounds,the effect of 1-2 rounds is good.The auxiliary tube adjustment is adjusted once every3 rounds of production,and each time is adjusted 40-50 meters,with the best effect.The suggestion of increasing yield under high wheel is put forward,which has certain practical guiding significance for similar horizontal well development under similar geological conditions.