Abstracts: The Horizontal Drilling Project in the Long Beach Unit, Wilmington Oil Field, California
BERMAN, BRIGITTE H.
The initial phase of horizontal drilling in the Long Beach Unit included 20 wells with a horizontal completion length from 800 to 1800 feet producing bypassed oil from the Ranger Zone. Two targets are being pursued: the upper 30 feet of the thick Upper Ranger FO sand and Lower Ranger undepleted thin bedded sand packages.
Performance of the FO-horizontal wells shows a hyperbolic decline. Initial oil production is as anticipated from log derived oil saturation. However, within half a year water coning is evident. To better understand well performance and aid in new well placement, the FO sand was simulated in the target area. Incorporated in the simulation was a geologic model which consisted of mapping the continuity of the intermittent shale barriers. The simulator addressed water injection effects of these shale barriers on the FO reservoir.
Initial performance of horizontal wells completed in the thin bedded sand packages is as predicted, good oil rate and low wafer cut production. Despite an ongoing waterflood, these wells exhibit a rapid gross and net production decline with time. Petrographic analyses were made in the thin bedded sand/shale intervals. Improved reservoir description and assessment of formation damage and potential led to a better understanding of reservoir behavior. Geosteering with MWD/GR and a 2MHz dual propagation resistivity tool is used to the casing point The new slim hole multiple propagation resistivity tool has greatly improved geosteering in the horizontal section of the wells where previously only MWD/GR were used. All phase one wells were drilled with a large radius trajectory. The introduction of medium radius drilling has reduced drilling costs substantially. The second phase of horizontal drilling mainly targets infill drilling between horizontal wells needed to deplete reserves. The horizontal drilling program in the Long Beach Unit is an economic success and will, in the future, expand into short radius drilling and bilateral completions.
Search and Discovery Article #90945©1997 AAPG Pacific Section Meeting, Bakersfield, California