Integrated Reservoir Characterization of a Tulare Steamflood Finds Bypassed Oil - South Belridge Field, Kern County, California

D. R. Walter, A. S. Wylie Jr., and K. A. Broussard

Reservoir quality and producibility are directly related to the characteristics of the depositional lithofacies. Electric log gamma ray/resistivity profiles were used to define facies trends within the Tulare steamflood at South Belridge. Channel and non-channel facies profiles are distinctive across the lease with the channel sands having the better quality reservoir and greater net pay values. Sidewall core permeabilities were averaged over the main producing Tulare intervals with the channels averaging 2000-3000 millidarcies and non-channels 200-500 millidarcies. This supports the lithofacies trend and net pay maps. Although the approach is qualitative, it illustrates the dramatic permeability contrast between the channel and non-channel lithofacies.

Temperature maps using downhole temperature surveys and flowline temperatures indicate channel facies temperatures up to 300 degrees with the non-channel facies having 90° to 100° temperatures (near ambient). Higher temperatures also relate to higher average daily production rates for channel associated wells. Channel wells averaged greater than 30 BOPD while non-channel wells averaged 10 BOPD or less. New and replacement well locations have been high graded resulting in favorable production responses.

Integration of the lithofacies, permeability and temperature data plus ongoing preventive production optimization work has led to a more efficient Tulare steamflood and identification of bypassed oil on the King-Ellis lease in the South Belridge Field.

AAPG Search and Discover Article #91019©1996 AAPG Convention and Exhibition 19-22 May 1996, San Diego, California