Development of the Marvic/Spellacy Sands at Bremer, Midway-Sunset

Osama Karaman, Karen Blake, and Greg Bowers
Plains Exploration & Production Company, 1200 Discovery Drive #500, Bakersfield, CA 93309

The Bremer Fee property is in the northern part of the Midway-Sunset field which lies along the eastern flank of the Temblor Range. Mio-Pliocene Potter sands have been highly developed with recovery to date of approximately 50% of original-oil-in-place. The lesser developed Miocene Antelope sands include the D Channel, Marvic and Spellacy. Recent efforts have focused on Marvic/Spellacy development. The Marvic Sands depositional environment is that of a submarine canyon to upper submarine fan channel; characterized by a large percentage of low porosity, poorly sorted, conglomerate facies. The Spellacy Sands were deposited in a mid-to-upper fan channel system characterized by moderately to poorly sorted sands with some interbedded diatomite layers. Early studies involved a water sensitivity test of the Marvic using a core plug sample from Santa Fe Energy well 281-17N in 1987 and concluded that the formation would not be damaged by fresh water or steam injection. Enhanced recovery using steam injection in the Spellacy has been conducted in the southern half of the Midway-Sunset field since the 1960’s. A steamflood pilot study in the Marvic/Spellacy in the eastern area of the Bremer Fee property began in 1996 using four inverted 5-spot patterns. The initial response was 150 bopd. Reviewing the results of the initial pilot study, Reservoir Engineering concluded that an inverted 9-spot pattern should be more efficient. Three infill wells were drilled in 2004 increasing the production by 150 bopd. The remaining 9-spot wells in the four pattern pilot area were drilled in 2005. Production peaked at 400 BOPD in 2007.

Nine step-out wells were drilled in 2005 along the western property boundary where the Marvic/Spellacy proved to be thicker than in the eastern four pattern steamflood pilot area. In 2007, thirty additional wells were drilled and cored in the Marvic/Spellacy. Insight on the differences between the western flank of the southeasterly plunging anticline and the eastern flank were provided by a 3D model. Production rate differences were first noted by Operations, which concluded that the western flank required larger pumping units. Work is ongoing to create a petrophysical model as test results become available. Total Marvic/Spellacy production is approximately 1,400 BOPD and increasing.

AAPG Search and Discovery Article #90076©2008 AAPG Pacific Section, Bakersfield, California