Managing Hydrocarbon Injectionat At Judy Creek

Abstract

Abstract Tile Judy Creek Beaverhill Lake ‘A’ and ‘B’ Pools have been undergoing pattern hydrocarbon miscible flood (HCMF) since 1985 and 1987 respectively. This paper describes the evolution of the hydrocarbon injection strategy for the Judy Creek Pools from 1985 to today. The original HCMF design for each pattern was a water-alternating- gas (WAG) ratio of 1.0. minimum solvent bank of 15% of the continuous hydrocarbon pore volume (CHCPV), and a minimum chase gas bank of 20% of the CHCPV. Analysis of performance data has resulted in an evolution of HCMF design parameters and operating strategy, injection strategy is now specific to each pattern and zone. Downhole isolation equipment has been used extensively to improve zonal control leading to better reservoir sweep: examples of this are presented. Both ofthese changes have significantly improved tertiary recovery, but also have greatly increased the data management required. Imperial Oil's current method of designing, scheduling, and reporting hydrocarbon injection banks and WAG ratios by pattern and geologic zone is discussed. This includes a computer program that has been developed to calculate pattern and zonal hydrocarbon banks and WAG ratios. Approximately 1,400 103m3/d (50 mmcf/d) of hydrocarbon is injected into the Judy Creek HCMF3. Optimal use of injectant is a key lever in maximizing profitability of these hydrocarbon miscible floods. Introduction The Judy Creek "A" and "B" Pools are located about 200 km northwest of Edunonton. Alberta, and were both discovered in 1959. Figure 1 is a gross thickness of 70m (230 ft). The "B" pool is geologically similar but smaller its original oil in place is estimated at 39.8x 106 m3 (250 MMSTB) and it covers an area of 4.915 ha (12,000 acres). Examples from both pools have been included, but the paper will focus on the "A" pool. Geologically, the "A" Pool is an atoll-like reefal limestone. It can be generally described as a highly porous organic reel margin surrounding a more stratified interior lagoon. Figure 2 shows a cross-section through the reef. Pore volume and continuity vary widely. The reef margin geology exhibits high porosity and permeability and good lateral and vertical continuity. In contrast, the ref interior is characterized by varying porosity and permeability, with thin pay zones separated by thicker tight streaks. There is poor lateral and vertical community. Core studies have defined five cycles of reef growth (denoted as the R1 and R5 zone). Except in the reef margin, there is no vertical flow between these boundaries. The "A" pool was originally developed on 64 and 160 acre) well spacing, under solution gas drive. A peripheral waterflood scheme was implemented in 1964. In 1974, a pattern waterflood scheme was implemented, as he penpheral waterflood injections were unable to support production wells in the red interior In 1975 and 1978, extensive infill drilling occurred., reducing the well spacing to 32 ha (80 acre) in many areas off the pool.