Brunei
Society of Petroleum Engineers (SPE) Evening
Distinguished
Lecture Series:
“Downhole Water Separation” by Mr Andrew K Wojtanowicz
Date: 8th April 2004
Venue: Rivera Hotel, Kuala Belait
ABSTRACT
During the economic life of a producing
field, the volume of produced water may exceed the volume of hydrocarbon
produced by 10 times. During late stages of production, it is not uncommon to
find that produced water can account for as much as 98% of the extracted fluids.
Historically, the average worldwide water cut is 75%, while the average water
handling Opex cost to the oil industry is $0.50 per barrel of water, amounting
to $40 billion total.
Since the conventional process of fluid
separation is energy intensive and very costly, the industry has searched for
innovative techniques that would move the separation upstream the production
process, i.e. to the wells’ bottom, or even back to the reservoir.
The presentation will introduce modern
technologies for separation of water in oil and gas wells. In principle, these
techniques fall into one of two categories: bottomhole separation and separation
in situ. The bottomhole separation techniques utilize separation inside the
well. Discussion will include bottomhole systems based on gravity separation of
gas and water (modified plunger, bypass tool, ESP) and gravity separation of oil
and water—dual/triple action pumping (DAPS/TAPS), hydraulic submersible pump (HSP),
and horizontal gravity separator (HSep). The discussion will include field
performance and several case histories, since some of these systems have been
successfully commercialized.
Also presented will be the downhole oil
water separation (DHOWS) technology using bottomhole mechanical
separators—hydro cyclones with or without ESP. The presentation will discuss
downhole installation and completion aspects of these techniques as well as the
limitations of hydro cyclones as separation devices. Several case histories of
DHOWS demonstration projects will be also presented.
The final part of the presentation will concern a dual-completion technology using in-situ separation of water from oil or gas in the reservoir outside a producing well (downhole-water-sink technology, or DWS). In DWS wells, the second (bottom) completion is used for draining water in order to maintain the well’s potential for production of oil/gas from the top completion. Explained will be principles of DWS well performance in the bottom water and edge water reservoirs. A case history will show details of downhole installation and production data. Also discussed will be the comparison of DWS with conventional wells and incremental recovery due to the technology.
BIOGRAPHY
Andrew K. Wojtanowicz is Texaco-endowed Environmental Chair in Petroleum Engineering at Louisiana State U. and U.N. expert in drilling engineering. He has worked in the petroleum industry as a drilling engineer, drilling supervisor, and drilling fluids technologist in Europe and Africa. Wojtanowicz has held faculty positions at three universities and conducted research in drilling, completion, and production operations with emphasis on environmental effects and prevention techniques. His studies are reported in 180 publications and four books. He is an Editor-in-Chief of ASME Transactions Journal of Energy Resources Technology and a registered petroleum and environmental engineer in Louisiana. As a Conoco Environmental Research Fellow ’91/92, he developed dewatering technology for closed-loop drilling systems. He has also developed water coning-control technique with Downhole Water Sink (DWS) well completion, for which he received Special Meritorious Award for Engineering Innovation in 1996. He has directed a DWS Joint Industry Project at LSU since 1997
Pictures from the evening
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