Assessment of Artificial Lift Methods for a Heavy Oil Field in Kuwait

Abstract

This paper describes a systematic assessment artificial lift method for a heavy oil development in Kuwait. The main recovery strategies taht were being cosnidred for the development consisted of different sequencing of primary production, cyclic steam stimulation and steam flooding, with both vertical and horizontal wells.

In 2007, Kuwait Oil Company drilled five vertical wells in their heavy oil fields, as a precursor to the full field development planned in the coming years. These five wells represented the first major activity in the formation since the 1980s when two cyclic steam stimulation pilot tests were conducted. The characteristics of the development and of the associated planned recovery strategies presented several AL challenges that needed to be assessed.

This work consisted of an assessment of the strengths and weaknesses of various AL systems and a ranking of these systems according to well geometry, oil viscosity, targeted flow rate and the recovery method. The assessment and ranking were mainly based on vendor quoted capabilities, focused wellbore modelling and lessons learned from other heavy oil field cases around the world. While significant experience with rod pumps in cyclic steams timulation exists in Canada, the lessons learned from that experience needed to be evaluated due to the differences with the Kuwait heavy oil development, such as the requirement to "easily" transition from primary to thermal production and the possible use of metallic stator progressing cavity pumps.

This paper provides guidance to other developments around the world in regards to heavy oil AL selection and how to best apply lessons learned from existing heavy oil developments.

Introduction

In 2007, Kuwait Oil Company(KOC) drilled five vertical wells in the Lower Fars formation, as a precursor to the full field developmented planned in the coming years. These five wells represented the first major activity in the formation since the 1980s when two Cyclic Steam Stimulation (CSS) pilots tests were conducted. The main recovery strategies that were being considered for the upcoming development consisted of different sequencing of primary production (with and without completion techniques to encourage sand production1), CSS and steam flooding. Both vertical and horizontal wells were also considered.

The characteristics of the development and of the associated planned recovery strategies presented several Artificial Lift (AL) challenges that needed to be investigated. Thus, in 2010, an AL system assessment was conducted. The ultimate objective was tor ank various AL systems for four scenarios representing the well, reservoir and fluid characteristics of the Lower Fars formation.

The assessment was mainly a qualitative assessment of the strengths and weaknesses of each AL system and focused on whether or not the expected requirments for the scenarios considered were within the limits of each AL system.2 The assessment did not include detailed equipment design of detailed economic analyses.

Author: Worth, D. J., Al-safran Eissa M, Choudhuri, A., & Al-Jasmi, A. K.

Publisher: SPE International Heavy Oil Conference and Exhibition, 8-10 December, Mangaf, Kuwait

Year: 2014

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