Application of Thomeer Hyperbolas to decode the pore systems, facies and reservoir properties of the Upper Jurassic Arab D Limestone, Ghawar field, Saudi Arabia: A “Rosetta Stone” approach

We investigated the basic geological and petrophysical properties of the multimodal pore systems in the Arab D limestone facies in Ghawar field, Saudi Arabia. The study used more than 500 mercury injection capillary pressure (MICP) data, which were type-curve matched using Thomeer Hyperbolas. The new MICP sample data were drawn from 10 cored wells that transect the Ghawar field from north to south and from a previous fieldwide study with 125 MICP samples. These 500 samples have a very rich statistical foundation in that they were selected using only random decimation within each of the facies from more than 3,500 core plugs all with assigned facies. In addition to MICP data and facies, a former, smaller sample set had both facies and Dunham texture codes. A new view of these pore systems emerged, that is built upon the intrinsic, fundamental and separate maximum pore-throat diameter modal elements named porositons. Porositons are stable, recurring and intrinsic modes in the maximum pore-throat diameter of the carbonate pore systems. Analytical results derived from the MICP data showed that the pore systems of the Arab D limestones can be classified based on porositons. The benefits of this new classification are demonstrated by considering in detail the relationships to geological facies, well-log responses, permeability modeling and simple nuclear magnetic resonance (NMR) well-log response. By analogy to the decoding of the Egyptian hieroglyphics using the Rosetta Stone, the use of porositons enables strong connections to be made between the geological facies, petrophysical and reservoir-flow properties of these complex carbonate rocks. The relationships between the new pore systems categories and the facies were thoroughly tested using north-south field trends.

[1]  J. Hawkins,et al.  Capillary pressure model predicts distance to gas/water, oil/water contact , 1993 .

[2]  E. Pittman.  Microporosity in Carbonate Rocks: GEOLOGICAL NOTES , 1971 .

[3]  D. Cantrell,et al.  Reservoir rock classification, Arab-D reservoir, Ghawar field, Saudi Arabia , 2003, GeoArabia.

[4]  A. H. Thompson,et al.  The microgeometry and transport properties of sedimentary rock , 1987 .

[5]  R. J. Dunham.  Classification of Carbonate Rocks According to Depositional Textures , 1962 .

[6]  M Ahr Wayne,et al.  Confronting the carbonate conundrum , 2005 .

[7]  Djebbar Tiab,et al.  Enhanced Reservoir Description: Using Core and Log Data to Identify Hydraulic (Flow) Units and Predict Permeability in Uncored Intervals/Wells , 1993 .

[8]  R. Bathurst.  Boring algae, micrite envelopes and lithification of molluscan biosparites , 2007 .

[9]  P. Harris,et al.  Giant Hydrocarbon Reservoirs of the World , 2006 .

[10]  Lithofacies, Diagenesis, and Depositional Sequence; Arab-D Member, Ghawar Field, Saudi Arabia , 1988 .

[11]  M. C. Leverett,et al.  Capillary Behavior in Porous Solids , 1941 .

[12]  D. Cantrell,et al.  Microporosity in Arab Formation Carbonates, Saudi Arabia , 1999, GeoArabia.

[13]  P. Harris,et al.  Giant Oil and Gas Fields , 1988 .

[14]  W. E. Ham.  Classification of Carbonate Rocks—A Symposium , 1962 .

[15]  J. H. Thomeer,et al.  Air permeability as a function of three pore-network parameters , 1983 .

[16]  R. F. Lindsay,et al.  Ghawar Arab-D Reservoir: Widespread Porosity in Shoaling-upward Carbonate Cycles, Saudi Arabia , 2008 .

[17]  J.H.M. Thomeer,et al.  Introduction of a Pore Geometrical Factor Defined by the Capillary Pressure Curve , 1960 .

[18]  F. Jerry Lucia,et al.  Rock-Fabric/Petrophysical Classification of Carbonate Pore Space for Reservoir Characterization , 1995 .

[19]  G. E. Archie,et al.  Introduction to Petrophysics of Reservoir Rocks , 1950 .

[20]  Pierre Delfiner.  Three Statistical Pitfalls of PHI-K Transforms , 2006 .

[21]  M. Al-Husseini.  Jurassic Sequence Stratigraphy of the Western and Southern Arabian Gulf , 1997, GeoArabia.

[22]  F. Lucia,et al.  Petrophysical Parameters Estimated From Visual Descriptions of Carbonate Rocks: A Field Classification of Carbonate Pore Space , 1983 .

[23]  P. Lawrence,et al.  Tilted original oil/water contact in the Arab-D reservoir, Ghawar field, Saudi Arabia , 2003, GeoArabia.

[24]  P. Choquette,et al.  Geologic Nomenclature and Classification of Porosity in Sedimentary Carbonates , 1970 .

[25]  D. Heling.  Microporosity of Carbonate Rocks , 1968 .

[26]  Henri Elhai.  Lexique stratigraphique international , 1963 .