Horizontal wells are commonly used in bottom water reservoirs,which can increase contact area between wellbores and reservoirs.There are many completion methods used to control cresting,among which variable density pe...Horizontal wells are commonly used in bottom water reservoirs,which can increase contact area between wellbores and reservoirs.There are many completion methods used to control cresting,among which variable density perforation is an effective one.It is difficult to evaluate well productivity and to analyze inflow profiles of horizontal wells with quantities of unevenly distributed perforations,which are characterized by different parameters.In this paper,fluid flow in each wellbore perforation,as well as the reservoir,was analyzed.A comprehensive model,coupling the fluid flow in the reservoir and the wellbore pressure drawdown,was developed based on potential functions and solved using the numerical discrete method.Then,a bottom water cresting model was established on the basis of the piston-like displacement principle.Finally,bottom water cresting parameters and factors influencing inflow profile were analyzed.A more systematic optimization method was proposed by introducing the concept of cumulative free-water production,which could maintain a balance（or then a balance is achieved）between stabilizing oil production and controlling bottom water cresting.Results show that the inflow profile is affected by the perforation distribution.Wells with denser perforation density at the toe end and thinner density at the heel end may obtain low production,but the water breakthrough time is delayed.Taking cumulative free-water production as a parameter to evaluate perforation strategies is advisable in bottom water reservoirs.展开更多
Aiming at the large error in productivity predication and incomplete consideration in completion parameters design of perforated horizontalwell,a model which coupled the relationship of pressure and flow rate in reser...Aiming at the large error in productivity predication and incomplete consideration in completion parameters design of perforated horizontalwell,a model which coupled the relationship of pressure and flow rate in reservoir seepage,near-wellbore inflow and wellbore flow was established.The impact of near-wellbore heterogeneity,wellbore flow pressure drop and completion parameters on the inflow profile of horizontalwell is analysed.Studies showed that with a stronger near-wellbore heterogeneity,the inflowprofilewouldfluctuatemore seriously.Perforationdensityhada great influence onthe inflow profile and local changes of it would bring a shunt effect.Completion design of variable density perforated horizontalwell with an optimized inflowprofile whichwas close to a standard profilewould improve the horizontal well development effect.The achievement can provide directive meanings to productivity predication and completion parameters design of horizontal wells in oilfield.展开更多
文摘Horizontal wells are commonly used in bottom water reservoirs,which can increase contact area between wellbores and reservoirs.There are many completion methods used to control cresting,among which variable density perforation is an effective one.It is difficult to evaluate well productivity and to analyze inflow profiles of horizontal wells with quantities of unevenly distributed perforations,which are characterized by different parameters.In this paper,fluid flow in each wellbore perforation,as well as the reservoir,was analyzed.A comprehensive model,coupling the fluid flow in the reservoir and the wellbore pressure drawdown,was developed based on potential functions and solved using the numerical discrete method.Then,a bottom water cresting model was established on the basis of the piston-like displacement principle.Finally,bottom water cresting parameters and factors influencing inflow profile were analyzed.A more systematic optimization method was proposed by introducing the concept of cumulative free-water production,which could maintain a balance（or then a balance is achieved）between stabilizing oil production and controlling bottom water cresting.Results show that the inflow profile is affected by the perforation distribution.Wells with denser perforation density at the toe end and thinner density at the heel end may obtain low production,but the water breakthrough time is delayed.Taking cumulative free-water production as a parameter to evaluate perforation strategies is advisable in bottom water reservoirs.
文摘Aiming at the large error in productivity predication and incomplete consideration in completion parameters design of perforated horizontalwell,a model which coupled the relationship of pressure and flow rate in reservoir seepage,near-wellbore inflow and wellbore flow was established.The impact of near-wellbore heterogeneity,wellbore flow pressure drop and completion parameters on the inflow profile of horizontalwell is analysed.Studies showed that with a stronger near-wellbore heterogeneity,the inflowprofilewouldfluctuatemore seriously.Perforationdensityhada great influence onthe inflow profile and local changes of it would bring a shunt effect.Completion design of variable density perforated horizontalwell with an optimized inflowprofile whichwas close to a standard profilewould improve the horizontal well development effect.The achievement can provide directive meanings to productivity predication and completion parameters design of horizontal wells in oilfield.
