Abstract
Downhole Oil/Water Separation (DHOWS) with the
same wellbore disposal has received much attention in Canada in
recent years. One of the developments in this area is a system
of two reciprocating rod pumps that facilitates the separation
of oil and water in the wellbore. This creates a separation chamber
in the wellbore where oil and water are able to segregate due
to the force of gravity. No other mechanical means of separation
is required. One pump produces an oil rich stream to surface while
the other injects water to a disposal zone in the same well bore.
Both pumps discharge fluid on the upstroke. In this way the sucker
rod string is loaded in conventional sucker rod pumping manner.
This paper will review some basic criteria for
candidate selection followed by the more detailed aspects of candidate
evaluation. There will a technical discussion of wellbore configurations
and separation theory as it applies to candidate evaluation. Typical
and available pump sizing is presented along with their impact
on production goals. Non-typical system designs and possible future
development is addressed.
Finally, some case histories are reviewed with
respect to wellbore and fluid characteristics and comparison of
predicted design parameters vs. actual production results.
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