John H. Duerksen

Designing a Steamflood Pilot in the Thick Monarch Sand of the Midway-Sunset Field

This study describes the design and development of a steamflood pilot consisting of 6 inverted 5-spot patterns on Section 26C of Midway-Sunset field. The injection interval is the massive Monarch sand, which averages 300 ft thick and produces 14/sup 0/ API oil. Geological features, reservoir properties, and production history indicate favorable steamflood characteristics. A reservoir simulation study of this pilot indicates that 60 to 70% of the original oil in place can be recovered by steamflooding this thick sand. Important simulation parameters were relative premeability, steam injection rate, steam quality, producer bottom-hole pressure, dip angle, reservoir thickness, pattern area, and well completion intervals. Simulation results were used to determine injector completion intervals and to position 3 observation wells.

Status of the Section 26C Steamflood Midway-Sunset Field, California

This study describes the status of a 23-acre, 6-pattern steam-flood pilot in the thick (300 ft) steeply-dipping (10/sup 0/) Monarch Sand, Section 26-C, Midway-Sunset field, after 18 mo. of steam injection. The steam-flood response shows a significant increase in oil production (520 bpd) relative to cyclic stimulation response. The response is significantly affected by preferential permeability, areal confinement, and localized barriers to vertical flow. The observation well temperature profiles confirm that the low- permeability zone just above the steam-injection interval is at least a local barrier to vertical steam flow. Differences between steam-flood performance and previous simulator predictions were due to reservoir heterogeneities not accounted for in the simulator study.

Performance and Simulation of a Cold Lake Tar Sand Steam-Injection Pilot

The injection of steam to recover extremely viscous, heavy oil from the Cold Lake deposits of Alberta, has been field tested by several companies. Encouraged by the early results of the single-well pilot, Chevron Canada Resources Ltd. initiated a 7-well steam injection pilot in 1976. The general objective of the pilot was to evaluate the producing potential of the B channel sand and other sands of the Grand Rapids Formation. To mathematically simulate the cyclic steam response of the Cold Lake heavy oil sands, a fractured tar sand simulator was developed at Chevron Oil Field Research Co. This simulator was used to evaluate the effect of steam slug size on cyclic response from a single well and the effect of converting to steam drive on pilot response. This study reports on performance of the pilot and the results of the simulation study. 14 references.