An Integrated Life-Time Artificial Lift Selection Approach for Tight/Shale Oil Production

Abstract

Abstract The application of horizontal drilling coupled with hydraulic fracturing technology has enabled tight oil economic production from tight oil reservoirs (well known as "shale play"). In North America, tight oil production has emerged as a reliable crude oil source. The contribution from tight oil resources is expected to grow further and could share a significant amount of future energy demand. However, the challenge is to produce difficult reservoirs economically, and key enablers are identification of "sweet spots" and well placement optimization, improving drilling efficiency, optimizing stimulation treatment and decline rates/OPEX reduction. The main challenge for long economical production is high decline rate –normally production rates could drop to 70 percent of initial rates after the first year. There are basically three reasons of such reservoir behavior: transient inflow effect, no pressure maintained and fractures deterioration. Handling of high variety of production rates with high efficiency is a significant challenge to artificial lift technique. This paper presents an integrated life-time artificial lift selection approach to optimize bottom-hole pressure and production lifting efficiency and therefore minimize production OPEX. The methodology incorporates integrated fit-for-purpose modelling approach, with taking into account the most important factors like transient reservoir behavior, lifting efficiency, equipment reliability and economics. The procedure is based on production optimization by determination of artificial lift method change necessity over well life and optimal switching point finding. The main criterion for the technique selection is a generation of maximization of value (like NPV) with minimal risks over well-life within given production constrains.