S.K. Sohoshko
Tyumen state oil and gas University, Russia
Title: Modeling oil well operation at a stabilized production flow rate with a complex bottomhole design
Biography
Biography: S.K. Sohoshko
Abstract
Currently, as a result of evolution of borehole techniques and development of drilling engineering it is increasingly common to see a well having a complex design. Verticalwells with radial horizontal sections of the wellbores can have a combination of open hole and perforated completion designs. Therefore it remainshighly important to carry out performanceevaluations of such wells depending on a well design, scheme of formation penetration, as well as formation productivity and even individual well intervals productivity. In addition to that it is necessary to resolve the problem of poor inflow to the areas of perforated and open-hole well sections in case of their combined use. This paper contains theanalysis of the inflow to the horizontal open-hole section of the oil well operating at stabilized production flow rate in a homogeneous anisotropic formation with impermeable top and bottom in presence of external reservoir boundaries. The solution has been obtained using a flowing pressure based estimate function of a stabilized production flow rate with integration ofindividual well intervals. Interferences of individual wellintervals were considered. The calculations of the well flow took account of the local drags occurring in a twisted flow at the wellbore entrance. The resulting solution has a good precision rate compared to the known analytical solutions. The problem solution for the vertical perforated well was also obtained using the flowing pressure based estimate function contemplatinginterferences of perforations. Local drag and hydraulic resistances along the well were also considered. The analysis of combined operation of the vertical perforated section of the well with a horizontal open radial wellbore takes into account interferences of local drags occurring in places where they attach to one another, as well as interferences occurring along the well. The paper includes calculation results of operation of perforated vertical oil well with a radial horizontal open wellbore bearing in mind interferences of perforated section and the open wellbore, as well as existing hydraulic flows into thewell. A significant pressure drop can be seen at theirconnection place. The developed software allows calculations of well and individual well productivity intervals as fluid inflow profiles, increased flow rate in the well, well pressure drop based on formation of geological layers and physical parameters, diameter and length of the individual well intervals. The software also allows calculations of multilateral completion of wells having more complex designs using a similar principle.