Critical Heterogeneities in a Barrier Island Deposit and Their Influence on Various Recovery Processes

Abstract

This paper synthesizes geologic information, acquired from the literature and field studies, and provides detailed maps of geologic heterogeneities, obtained from log and core data, of the Bell Creek field, MT. Geologic heterogeneities were correlated with fluid production data to identify the heterogeneities that have a dominant effect on fluid production. Integration of new and existing information from various geological, geophysical, and engineering disciplines allowed us to identify heterogeneities that influence production during different recovery operations.

Determining the Productivity of a Barrier Island Sandstone Deposit From Integrated Facies Analysis

“…This sudden increase is believed to result from an increase in diagenetic clays. 5 From the central part, the average total clay content along Profile AA' decreases in either direction. On the lagoonal side, in the eastern extremity of Profile AA', a 5.4% increase occurs in average clay content in the highly productive (washover) facies.…”

“…The geological and petrophysical properties of reservoir rocks in the Bell Creek field have been reported. 4,5,9,10 The porosity, permeability, and pore-throat sizes of these sandstones depend primarily on (1) grain size and sorting, (2) amount and types of clays and their mode of distribution in the pore spaces, and (3) amount of cementation and compaction. We studied 17 cores from the central part of Unit A within the area of the U.S. DOE's Tertiary Oil Incentive Program (TIP) and two cores from the southwestern part of the field (Fig.…”

“…5 -7 Paleogeographic and paleotectonic reconstructions of the Muddy formation show the interrelationship between continental (delta channels and deltaic plain), brackish marine (lagoon, estuary, and tidal flat), and coastal marine (barrier islands) sedimentation in the northeastern Powder River basin where Bell Creek field is located. [4][5][6][7][8] The entire Muddy sandstone assemblage and its related depositional environments (lagoonal, estuary, tidal flat, tidal channel, and valley fill) are under-and overlain by marine shalesi.e., Skull Creek and Shell Creek/Mowry shale, respectively.…”

Research needs for strandplain/barrier island reservoirs in the United States

“…) in the rock matrix, and variations in other reservoir parameters such as pressure and temperature. Sharma et al (1990) defined the term as "any change in geologic reservoir properties that causes a variation in fluid-flow parameters (e.g., permeability, porosity, fluid saturation, and capillary pressure) that results in modification of the flow regime." These variations have a profound influence on the movement characteristics and flow patterns of singleand multiphase fluids in the subsurface.…”

“…The Bell Creek field consists of six separate barrier island reservoir compartments in which the trapping mechanism is the updip pinch-out of barrier core facies into lagoonal shales. The predominant heterogeneities affecting production in this micellar-polymer project were (1) facies architecture and the presence of incised valleys with lithologically variable fill (Szpakiewicz et al, 1987;Honarpour et al, 1988;Sharma et al, 1990;Burt et al, 1975); (2) distribution, type, and amount of authigenic clay minerals; and (3) presence of previously unrecognized fractures and faults between wells and groups of wells. Production data and pressure-pulse tests confirmed many of these naturally occurring heterogeneities, but interpretation of tracer survey results was not clear because of chemical interaction between the preflush and micellar-polymer solution (Szpakiewicz et al, 1987).…”