Research On Optimization Of Drilling And Shut-in Scheme Of B3 Block

There are many problems,such as oil production is greatly affected,and water cut rises fast when water injection is recovered in actual drilling and shut-in process of major oilfields.To solve these contradictions and problems has become a top priority.At present,the theory of cyclic waterflooding tends to be perfect,and a lot of field practice has been carried out.However,combination of drilling and shut-in and cyclic waterflooding technology lacks the theory and experience to be used for reference.Therefore,it is necessary to conduct more in-depth and comprehensive research on optimization of drilling and shut-in process combined with mechanism and mode of cyclic waterflooding.Firstly,Typical drilling and shut-in test area is selected and fine geological models are established,including structural modeling,sedimentary facies modeling and attribute modeling.Development indexes of the whole region and single well are historically matched,including fluid production,oil production and water cut.The matching precision is over 90%.Secondly,Physical models are abstracted by choosing appropriate formation parameters.According to the theory of seepage mechanics,a mathematical model for calculating formation pressure distribution and bottom hole pressure under the condition of multiple oil layers production is established.The technical limits of single well shut-in range and pre-drilling shut-in time for different well patterns are determined.Thirdly,based on the conceptual model of drilling and shut-in process,numerical simulation research is carried out.Change law and technical limits of fluid production,oil production,water cut and water injection in shut-in and recovery stages of different well patterns are determined.Total shut-in time limits for different well patterns and different reservoirs are determined.The calculation precision is over 80%.Fourthly,Technical ideas and schemes of combination of drilling and shut-in process and cyclic waterflooding are established.Principle of wells and layers selecting of cyclic waterflooding is determined.Technical limits of combination of shut-in drilling and cyclic waterflooding of different well patterns are determined,including horizontal batch stop-injection limits,vertical subsection stop-injection limits,water injection recovering mode and time limits,recovering limits of fluid production of different reservoirs.Finally,based on the technical limits of combination of drilling and shut-in and cyclic waterflooding,reasonable drilling and shut-in schemes are designed,numerical simulation of test area is carried out,and development effect is predicted.By October 2017,compared with the original scheme,the cumulative oil production of the scheme combined with cyclic waterflooding increased by 6329.99 t,and water cut decreased by 0.14 percentage points.