Production Optimization for Progressive Cavity Pumps by Interconnecting a Steady-State Flow Simulator and a Black Oil Reservoir Model through Integrated Asset Management Software

Abstract

Abstract At a time when oilfield economics call for the most optimized strategies to produce a field or set of wells, reservoir understanding and artificial lift technologies merge as one combined solution to provide top-of-the-class analyses for optimized production and economic success for very challenging projects. One of the most critical aspects related to the economics of the production life cycle is the maximization of net present value (NPV). This becomes even more relevant for wells that have high capital investment and expensive operating costs. The objective of this paper is to describe the simulation workflow developed to integrate the interactive response of the reservoir as a response to the drawdown induced when artificial lift is placed within a well. Based on the reservoir response, artificial lift operational parameters can be adjusted at each step to maximize the total NPV for a group of wells in a field located in the Middle East. Sample data describes a case of five wells connected to the same facility and completed with progressing cavity pumps (PCPs). The individual wellbores containing the PCPs were simulated using a steady-state multiphase flow simulator. Single-well models were used to feed the surface network model with flow lines, chokes and a separator. At the reservoir level, a reservoir model for each well was created using a black oil simulator. The use of an integrated asset modeler enabled automated interaction among single models, network model and reservoir models, allowing the creation of an optimization workflow. The integrated asset management software optimized PCP speed for each of the five wellbores to maximize oil recovery, delay water onset and maximize NPV of the field for one year. The optimizer also had to consider several constraints at both the wellbore and surface facility level. Minimum bottomhole pressures needed to be maintained throughout the simulation to prevent the reservoir from depleting prematurely. Water production also had to be limited to match surface handling capacities. Finally, PCPs needed to be constrained based on a maximum operating speed and maximum horsepower consumption. The workflow created effectively integrated reservoir modeling with artificial lift performance to deliver an optimized operational sequence for the case study, presenting as results PCP speeds and NPV per month. The results of the simulation showed the potential to increase the NPV and oil production by 10.5% and 9.5% respectively. Furthermore, the current workflow is flexible enough to be extended to other forms of artificial lift and has the potential to fully optimize and evaluate complete fields.