Modeling Thermally Induced Strain in Diatomite
- James K. Dietrich (The Dietrich Corp.) | John Donald Scott (U. of Alberta)
- Document ID
- Society of Petroleum Engineers
- SPE Journal
- Publication Date
- March 2007
- Document Type
- Journal Paper
- 130 - 144
- 2007. Society of Petroleum Engineers
- 3 Production and Well Operations, 5.5 Reservoir Simulation, 5.5.8 History Matching, 5.2.1 Phase Behavior and PVT Measurements, 2.4.3 Sand/Solids Control, 4.1.5 Processing Equipment, 5.8.7 Carbonate Reservoir, 5.1.5 Geologic Modeling, 1.2.2 Geomechanics, 5.3.4 Integration of geomechanics in models, 4.3.4 Scale, 3.2.3 Hydraulic Fracturing Design, Implementation and Optimisation, 5.4.6 Thermal Methods, 5.3.9 Steam Assisted Gravity Drainage, 1.6.9 Coring, Fishing, 5.6.3 Pressure Transient Testing, 5.8.5 Oil Sand, Oil Shale, Bitumen
- 4 in the last 30 days
- 614 since 2007
- Show more detail
- View rights & permissions
|SPE Member Price:||USD 10.00|
|SPE Non-Member Price:||USD 30.00|
Diatoms and radiolarians are microorganisms that precipitate Opal-A to form siliceous tests that accumulate on the seafloor to form siliceous oozes. Progressive diagenesis of these deposits during burial results in thick, highly compressible reservoirs of exceptionally high porosity and low permeability, not unlike the chalk reservoirs of the North Sea. During burial and over time, the amorphous silica phase (Opal-A) becomes unstable and gradually changes in its structure to more stable, ordered Opal-A' and crystalline forms or phases of silica, namely Opal-CT and quartz. The Opal-A ? Opal-A' ? Opal-CT ? quartz transformation results in a naturally occurring densification and compaction process that is accelerated by an application of heat. Reservoir compaction and surface subsidence can usually be controlled by injecting fluid to control the effective stress. However, in heavy-oil diatomite reservoirs undergoing steam injection, the injected fluid causes competing effects: it controls effective stress to some degree, yet at the same time it accelerates compaction and subsidence.
This paper describes selected results of a diatomite laboratory testing program and features of a unique thermal reservoir simulator formulated to handle the effects on compaction caused by stress, temperature, and time-dependent strain (creep). Elevated temperature in amorphous Opal-A diatomite is shown to be capable of causing a sample compression of 25% or more and a severe reduction in permeability. The effects of thermally induced compaction are expected to accelerate surface subsidence as diatomite steam projects mature.
There is a class of problems involving reservoir compaction of cohesive rocks (e.g. chalk, shale, and diatomite) in which the effects of stress are of a second-order importance compared to those of temperature. The injection of cold seawater in North Sea chalk reservoirs under conditions of invariant effective stress has led to continued compaction and subsidence (Cook et al. 2001; Sylte et al. 1999). The North Sea chalks are nearly pure calcium carbonate, and it is well known that the solubility of calcium carbonate increases as the water temperature decreases. Thus, even under conditions of unchanging effective stress, one would expect gradually increasing dissolution of calcium carbonate and compaction as the reservoir temperature of the chalk (~ 270°F) is gradually lowered by cold seawater injection (Dietrich 2001). In the giant Wilmington field of California, the shaly siltstones that are interbedded with the unconsolidated sands have recently been shown to be much more susceptible to thermally induced compaction than to stress-induced compaction (Dietrich and Norman 2003). And finally, diatomite is known to undergo a silica-phase transformation as temperature is raised, whereby amorphous Opal-A is converted to a more dense, crystalline Opal-CT. The injection of steam into California diatomite reservoirs is expected to accelerate this naturally occurring process and lead to rapid densification and compaction. In each case, for chalk, shaly rocks, and diatomite, there is both a laboratory and field basis that demonstrates the dominant role played by temperature.
|File Size||1 MB||Number of Pages||15|
Ambastha, A.K., Kumar, M., Skow, L.A., and Evola, G.M. 2001. Evaluation of Cyclic Steam Operationsat Cymric 1Y Diatomite. Paper SPE 71500 presented at the SPE AnnualTechnical Conference, New Orleans, 30 September-3 October. DOI:http://www.spe.org/elibrary/servlet/spepreview?id=71500-MS.
Barenblatt, G.I., Patzek T.W., Prostokishin, V.M., and Silin, D.B. 2002. Oil Deposits in Diatomites: A NewChallenge for Subterranean Mechanics. Paper SPE 75230 presented at theSPE/DOE Improved Oil Recovery Symposium, Tulsa, 13-17 April. DOI:http://www.spe.org/elibrary/servlet/spepreview?id=75230-MS.
Chalaturnyk, R.J. 1996. Geomechanics of the Steam Assisted Gravity DrainageProcess in Heavy Oil Reservoirs. PhD dissertation. U. of Alberta, Edmonton.
Chase, C.A. Jr. and Dietrich, J.K. 1988. Compaction Within the BelridgeDiatomite. Paper SPE 17415 presented at the SPE California Regional Meeting,Long Beach, California, 23-25 March.
Chase, C.A. Jr. and Dietrich, J.K. 1989. Compaction Within the South BelridgeDiatomite. SPERE 4 (4): 422-428. SPE-17415-PA. DOI:http://www.spe.org/elibrary/servlet/spepreview?id=17415-PA.
Cook, C.C., Andersen, M.A., Halle, G., Gislefoss, E., and Bowen, G.R. 2001.An Approach to Simulating theEffects of Water-Induced Compaction in a North Sea Reservoir. SPEREE4 (2): 121-127. SPE-71301-PA. DOI:http://www.spe.org/elibrary/servlet/spepreview?id=71301-PA.
Dean, R.H., Gai, X., Stone, C.M., and Minkoff, S.E. 2006. A Comparison of Techniques forCoupling Porous Flow and Geomechanics. SPEJ 11 (1): 132-140.SPE-79709-PA. DOI:http://www.spe.org/elibrary/servlet/spepreview?id=79709-PA.
Dietrich, J.K. 2001. Discussionof an Approach to Simulating the Effects of Water-Induced Compaction in a NorthSea Reservoir. SPEREE 4 (4): 345. SPE-73134-PA. DOI:http://www.spe.org/elibrary/servlet/spepreview?id=71301-PA.
Dietrich, J.K. and Norman, M.R. 2003. Steam Flooding Intensifies Subsidenceat Wilmington Field. Oil & Gas J. 101 (17): 41-50.
Fassihi, M.R., Abu-Khamsin, S., Brigham, W.E., Williams, L.A., and Graham,S.A. 1982. A Preliminary Study ofIn-Situ Combustion in Diatomites. Paper SPE 10701 presented at the SPEEnhanced Oil Recovery Symposium, Tulsa, 4-7 April. DOI:http://www.spe.org/elibrary/servlet/spepreview?id=10701-MS.
Interstate Oil Compact Commission. 1974. Secondary and Tertiary Oil RecoveryProcesses. Oklahoma City, Oklahoma: 131-132.
Johnston, R.M. and Shahin, G.T. 1995. Interpretation of Steam Drive Pilotsin the Belridge Diatomite. Paper SPE 29621 presented at the SPE WesternRegional Meeting, Bakersfield, California, 8-10 March. DOI:http://www.spe.org/elibrary/servlet/spepreview?id=29621-MS.
Koh, C.J., Dagenais, P.C., Larson, D.C., and Murer, A.S. 1996. Permeability Damage in Diatomite Dueto In-Situ Silica Dissolution/Precipitation. Paper SPE 35394 presented atthe SPE/DOE Improved Oil Recovery Symposium, Tulsa, 21-24 April. DOI:http://www.spe.org/elibrary/servlet/spepreview?id=35394-MS.
Kovscek, A.R., Diabira, I., and Castanier, L.M. 2000. An Experimental Investigation ofPermeability and Porosity Alteration in Diatomite During Hot FluidInjection. Paper SPE 62558 presented at the SPE/AAPG Western RegionalMeeting, Long Beach, California, 19-22 June. DOI:http://www.spe.org/elibrary/servlet/spepreview?id=62558-MS.
Kumar, M. and Beatty, F.D. 1995. Cyclic Steaming in Heavy OilDiatomite. Paper SPE 29623 presented at the SPE Western Regional Meeting,Bakersfield, California, 8-10 March. DOI:http://www.spe.org/elibrary/servlet/spepreview?id=29623-MS.
Lorenz, J.C., Warpinski, N.R., Branagan, P.T., and Sattler, A.R. 1989. Fracture Characteristics andReservoir Behavior of Stress-Sensitive Fracture Systems in Flat-LyingLenticular Formations. JPT 41 (6): 615-622; Trans.,AIME, 287. SPE-15244-PA. DOI:http://www.spe.org/elibrary/servlet/spepreview?id=15244-PA.
McGuire, M.D. 1983. Diagenetically Enhanced Entrapment ofHydrocarbons—Southeastern Lost Hills Fractured Shale Pool, Kern County,California. Presented for the Society of Economic Paleontologists andMineralogists, Pacific Section, Los Angeles.
Scott, J.D. and Seto, A.C. 1986. Thermal Property Measurements on Oil Sands.JCPT 25 (6): 70-77.
Settari, A. and Walters, D.A. 2001. Advances in Coupled Geomechanical andReservoir Modeling With Applications to Reservoir Compaction. SPEJ6 (3): 334-342. SPE-74142-PA. DOI:http://www.spe.org/elibrary/servlet/spepreview?id=74142-PA.
Sylte, J.E., Thomas, L.K., Rhett, D.W., Bruning, D.D., and Nagel, N.B. 1999.Water Induced Compaction in theEkofisk Field. Paper SPE 56426 presented at the SPE Annual TechnicalConference and Exhibition, Houston, 3-6 October. DOI:http://www.spe.org/elibrary/servlet/spepreview?id=56426-MS.
Williams, L.A. and Crerar, D.A. 1985. Silica Diagenesis, II. GeneralMechanisms. J. of Sedimentary Petrology 55: 312-321.
Williams, L.A., Parks, G.A., and Crerar, D.A. 1985. Silica Diagenesis, I.Solubility Controls. J. of Sedimentary Petrology 55: 301-311.