Downhole Fluid Analysis – The Key to Unraveling Reservoir Complexities

Friday, January 30, 2009 - 2:00 p.m. to Saturday, January 31, 2009 - 2:55 p.m.

ChEMS Seminar

Featuring Oliver C. Mullins, Ph.D.
Scientific Advisor in Wireline Headquarters, Schlumberger

Location:  Donald Bren Hall,  Room 1300
Free and open to the public

Abstract:
In recent years, there has been a growing realization that improper treatment of reservoir complexities such as compartmentalization and fluid compositional variation commonly lead to gross inefficiencies in facilities design, production strategies and predicted production; new methods are mandated. Previous working assumptions of homogeneous distributions of hydrocarbons in giant reservoir ‘tanks’ are now understood to be uncommon; one must prove not assume the value of the reservoir. The central questions arise: how can we identify fluid compositional variations in the reservoir and how can we use these measured variations to understand reservoir architecture (all within an acceptable cost structure)? 

Downhole Fluid Analysis (DFA) is the key. DFA is a new technology with rapidly expanding applications; DFA is used in virtually all market conditions today. By performing DFA measurements on fluid properties in-situ in oil wells, one can match the complexity of the hydrocarbon column to the complexity of the fluid analysis program. The operating company pays only for what they need. The methodology is enabling a quasi ‘continuous downhole fluid log.’ In petrophysics, continuous logs are the norm, but the oil column is not similarly respected, typically just a few fluid station measurements are employed - ironic in that we are in the oil business, not the rock business.  By understanding the variation of fluid properties, we can often identify compartments and other reservoir complexities. For example, density inversions, higher density fluids higher in the column, strongly imply sealing barriers. In  addition, connectivity can be strongly implied under certain circumstances. For example, we have recently discovered an asphaltene gradient in a large fluid column. Any newly penetrated sand with a contained fluid on this gradient has a good chance of being hydraulically connected. As will be described, the optimal DFA process involves partnership of the service company with the operating company. 

About the Speaker:
Oliver C. Mullins, Ph.D., a scientific advisor in Schlumberger, is the originator of Downhole Fluid Analysis, a significant new service in the oil industry, for which he has awarded three Gold Medals, two from Schlumberger and one from the State of Connecticut. The corresponding tools exploit near-infrared and fluorescence spectroscopy and are being used to uncover compartmentalization and hydrocarbon fluid complexities in subsurface formations. His current position, Reservoir Domain Champion for Wireline Headquarters reflects his contributions in this area. DFA acceptance by the industry is reflected in Dr. Mullins’ previously being SPWLA Distinguished Lecturer and SPE Distinguished Lecturer.