Abstract

This paper is a description of a system which separates the produced oil and water in a high WOR (Water Oil Ratio) well, injects the produced water, and pumps the oil to the surface. The unique feature of this system is that the production, separation, and injection are all accomplished downhole, in one wellbore.

The benefits to the operator include decreased lifting and disposal costs and improved product margins and reserve recovery. Conceptual application and design, and actual field trial histories are discussed. This paper is an update of the paper presented at the SPE 1996 ESP Roundtable in Houston1.

Introduction

A primary reason for the abandonment of crude oil producing wells is the large volume of water which is produced in conjunction with oil. Water production increases power, disposal, maintenance, chemical, capital and many other costs associated with producing oil. Additionally, high water saturation near the wellbore may adversely affect the flow of crude oil into the wellbore through relative permeability effects. The net effect of this water production is decreased producing margin and fewer recoverable reserves.

C-FER (Centre for Engineering Research Inc.) and New Paradigm Engineering conceived the idea of running a Hydrocyclone separator in series with a downhole pumping system to accomplish oil production, oil/water separation, and injection of the produced water in one wellbore. C-FER was granted a patent on this technology and there are other patents pending by both REDA and C-FER.

In 1992, C-FER approached Vortoil Separation Systems and REDA, seeking their involvement in the development and field testing of Electric Submergible Pump (ESP) Separation Systems through a joint industry development project.

Thirteen units have been installed to date.

Benefits of Downhole Separation

The general benefits of downhole separation include decreased lifting and disposal costs and improved product margins and reserve recovery. Specific potential benefits of downhole separation include:

  • Decreased power costs

  • Decreased maintenance costs

  • Decreased chemical costs

  • Decreased environmental hazard

Keywords:
downhole fluid disposal, downhole fluid management, oil production, downhole fluid separation, separator, enhanced recovery, joint industry development, downhole oil water separation, hydrocyclone separator, injection zone
Subjects:
Improved and Enhanced Recovery, Professionalism, Training, and Education, Information Management and Systems, Downhole fluids separation, management and disposal, Communities of practice, Knowledge management, Well Operations and Optimization, Well Operations, Optimization and Stimulation
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1997. Society of Petroleum Engineers
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