- Home
- Conferences
- Conference Proceedings
- Conferences
Third EAGE Workshop on Arabian Plate Geology
- Conference date: 28 Nov 2011 - 01 Dec 2011
- Location: Kuwait City, Kuwait
- ISBN: 978-94-6282-058-6
- Published: 28 November 2011
41 - 51 of 51 results
-
-
Microfacies, Diagenesis and Reservoir Quality of Early Triassic Kangan Formation in Offshore Zagros: A Case Study
Authors F.K. Harchegani and M.R. Kamali and B.E. DizajiSignificant amounts of hydrocarbon resources are hosted by the Lower Triassic Kangan Formation (Upper Khuff equivalent) in the southern part of Gulf. This carbonate gas reservoir is known to be a complex carbonate system with a high degree of heterogeneity, which has a direct impact on the reservoir quality. The formation consists mainly of limestone, dolomitic limestone, dolomite and evaporites. Combined core examinations and detailed thin section studies are used for facies analysis. Accordingly, 10 major facies were recognized in the Kangan reservoir. They are grouped as five facies assemblages deposited in supratidal, intertidal, lagoon, shoal and off-shoal environments. These facies associations reflect an ideal shallowing upward sequence. These facies are genetically related and indicate a gentle depositional gradient and morphology during deposition. Thus, they represent the shallow part of a homoclinal carbonate ramp (Figure 1). This interpretation is based on the characteristics of the constituent facies, lateral and vertical relations between sedimentary facies and the presence of thick succession of shallow-water deposits (high relative proportion of peritidal and lagoon versus open-marine facies).
-
-
-
Prospectivity of Khuff Reservoir in Southwest Kuwait
Authors M. Rahaman and M. Ebrahim and S. Al-GhareebThe Permian–Triassic Khuff Formation is an extensive gas reservoir in the Arabian Gulf area. The formation houses the world’s largest gas accumulation: the combined North Field (Qatar) and South Pars (Iran) dome, contain approximately 1,500 TCF of gas (Halbouty, 2003). The formation was deposited during a regional transgression over a stable shelf of very low relief, which had minor clastic supply on the margin of Arabian Peninsula. The porosity and permeability of the Khuff carbonate reservoirs are generally very low in the entire Middle East. Ehrenberg (2007) showed that porosity in the Middle East varies from 2–14%, where the depth of reservoir varies from 2–5.5 km. To explore the Khuff reservoir prospectivity, post–stack seismic inversion and porosity modeling was carried out using recently acquired 3- D Q-Land seismic data. The study area consists of two major fields, Minagish and Umm Gudair, which are located over major structural highs. In the southwestern part of the Kuwait only one well was drilled to the Khuff-C reservoir over the structural high of West Umm Gudair Field. Here the Khuff-C reservoir occurs at greater depth and is around 350 feet thick. The observed porosity of the unit is around 2.0%. The testing of the unit could not be carried due to mechanical problem.
-
-
-
Improving the Mapping of Permian–Triassic Layers using Inversion with Inter-bed Multiple Method: A Case Study of Mutriba Field, Kuwait
Authors Osman Al-Khaled, Y. Al-Zuabi and M. Rahaman and M. HafezThe onshore Mutriba Field, located in northwest Kuwait, shows some potential gas targets in the Lower Triassic to Permian formations. These levels are well known in the Middle East for being severely contaminated by coherent inter-bed multiple reflection events in the seismic data. These multiples have the same velocities as the primaries and cannot be adequately attenuated during processing. As a result, the acoustic impedance (AI) predicted from such seismic data is significantly affected. We present here an inversion study, which incorporates an Inter-Bed Multiple Modeling (IBMM), into the generation of synthetic seismograms, which are involved into the seismic inversion workflow.
-
-
-
Integrated Formation Evaluation and Production Potential of Pre-Jurassic Formations in Kuwait
Authors A. Rabie, R. Husain and M. Al-Mukhaizeem and A.M. Al-FaresThe Permian–Triassic Khuff Formation is an important hydrocarbon exploratory target in view of its proven potential in countries adjoining Kuwait. The formation, divisible into A, B, C and D units, is comprised of dolomite and limestone (mudstone-wackestone with rare packstone and grainstone) with subordinate shale and anhydrite. The formation is interpreted to be deposited in sub-tidal to supra-tidal environment with development of shoal and lagoon under hyper-saline conditions in restricted setting. Diagenetic history is complex and sediments have undergone multiple diagenetic events that include micritization, dolomitization, anhydrite cementation, leaching, stylolitization, fracturing and fracture filling. In the north, the formation is over dolomitized and can be categorized as tight nonconventional reservoir. In the west the formation has shown development of grainstone in Khuff C with significant porosity preservation. Here, the formation has shown hydrocarbon potential on logs but the testing results did not match the conventional log interpretation. This has adversely impacted the hydrocarbon assessment of this formation. To analyze the inconsistency, petrophysical and testing data were re-evaluated.
-
-
-
Post-stack Seismic Processing Refinement Facilitating Khuff and Pre-Khuff Exploration: Case Study from Shallow Marine Offshore Abu Dhabi
Authors M. Mahgoub and Saif Al-MesaabiThree 3-D ocean-bottom cable (OBC) seismic surveys acquired in offshore Abu Dhabi have been subjected to ADNOC’s in-house post-stack seismic refinement routine. The objectives were to resolve the tuning effects caused by various stratigraphic features and enhance fault imaging at the deep Khuff and pre-Khuff targets. There were some remaining persistent issues, such as: (1) noise; (2) strong short wavelength jitters of the acquisition footprint, which degraded the stack continuity even at depth; (3) multiples; and (4) the relatively lowfrequency bandwidth of the final data. These issues hampered the interpretation of the data after the imaging stage.
-
-
-
Sequence Stratigraphy of the Permian–Triassic Upper Khuff Carbonates, Ghawar Field, Saudi Arabia
Authors R.K. Al-Dukhayyil and J.F. Read and A.A. Al-TawilOver 1,500 meters of Upper Permian Khuff B/C and Early Triassic Khuff A and B cores and wire-line logs from 16 wells in Ghawar Field were studied. The carbonate-evaporite successions are interpreted to be arid epeiric ramp facies, which include: subaqueous laminated-and supratidal nodular- to massive anhydrite, tidal flat laminites, lagoonal mudstone, (with thrombolites restricted to Triassic), ooid-peloid shoal complexes, and subtidal off-shoal mudstone. Facies are packaged into meter-scale parasequences, often separated by exposure surfaces at sequence boundaries.
-
-
-
The Application of Phytolith Stratigraphy to ‘Barren’ Red-beds
Significant oil and gas reserves occur in so-called “barren red-beds” in several regions around the world. Although red-beds occur throughout the geological timescale, examples with an economic interest are the Late Carboniferous, Permian and Early Triassic of Europe (Barren Measures, Rotliegendes, Bunter; Doornenbal and Stevenson, 2010), the Triassic of the United States, and the Permian–Carboniferous of the Middle East. These sediments are generally deposited in nonmarine environments under arid climate conditions. In terrestrial basins, biostratigraphic analysis of plant microfossils (pollen and spores) is often effective in constraining static geological models. Unfortunately, such organic-walled microfossils are not preserved in red-bed deposits due to oxidation, hampering stratigraphic correlation on both local (field) and regional scale.
-
-
-
Heterogeneous Gravity Data Combination for Geophysical Exploration Research: Applications for Basin and Petroleum System Analysis in the Arabian Peninsula
Authors R.A. Fattah, S. Meekes, Y. Schavemaker, E. Guasti, J. Bouman and M. Schmidt and J. EbbingThe GOCE satellite gravity mission was launched in 2009 to measure the gravity gradient with high accuracy and spatial resolution. GOCE gravity data may improve the understanding and modeling of the Earth’s interior and its dynamic processes, contributing to new insights into the geodynamics associated with the lithosphere, mantle composition and rheology, uplift and subduction processes. However, to achieve this challenging target, GOCE should be used in combination with additional data sources, such as in-situ gravimetric, magnetic, and seismic data sets.
-
-
-
Breccia Beds in the Khuff (Permian–Triassic) in Ras Al Khaimah, United Arab Emirates: Collapse or Transgressive in Origin?
Authors S. Fontana, S. Morad, F.H. Nader and A. Ceriani and I.S. Al-AasmThe laterally extensive, so-called mid-Bih breccia beds occur in carbonate successions of the Upper Permian–Lower Triassic Khuff-equivalent Bih Formation in Ras Al Khaimah, United Arab Emirates (UAE). These carbonates have been deposited on a stable platform setting at the passive margin of the Neo-Tethys Ocean. The breccia beds have previously been interpreted to be formed by dissolution of sulphate beds by groundwater followed by collapse of overlying carbonate beds (Strohmenger et al., 2002; Fontana et al., 2010). Contrary to this earlier interpretation, we present several lines of field, petrographic, isotopic and fluid inclusion evidence suggesting that the “breccias” are intraformational conglomerates representing a major marine transgressive surface.
-
-
-
Delineation of Khuff Reservoir in Kra Al Maru Area of Kuwait Using Seismic Inversion and Lithology Modeling: A Case Study
Authors H. Shereef, O. Al-Khaled and Y. Al-Zuabi and T. Al-RashidA seismic reservoir characterization study was carried out over the Kra Al Maru structural trend in Kuwait to model the lithology of the Permian–Triassic Khuff reservoir. The dominant lithologies of the Khuff Formation are dolomites and dolomitic limestone with thin inter-beds of anhydrite and shale. The Khuff Formation has been divided into three units based on the lithological characters observed from one well. All three units contain dolomites, limestone, anhydrite and shale. The seismic data used was processed in 2005 with 25 meter bin spacing. Only one well was available for this study with the required log suite. The technique used was the Constraint Sparse Spike Inversion (CSSI) to produce the Acoustic Impedance (AI) volume. The principle objective of seismic inversion is to transform seismic reflection data into a quantitative Khuff rock property. A relationship between the acoustic impedance (AI) log and porosity log was established using the available well data to transform the AI volume to lithology volume.
-
-
-
Faults and Fractures in Carbonate Reservoirs: Khuff Formation of Arabian Peninsula
By A. MoustafaSeveral factors control the distribution of faults and fractures in reservoir rocks. These include the regional stress field, local strain due to the existence of larger structures, deformation history, presentday stress field, diagenetic changes, and mechanical stratigraphy. The regional stress field that affected the eastern part of the Arabian Plate since Permo-Triassic time involved extensional tectonics (leading to development of normal faults) during Permo-Triassic breakup of Gondwana and opening of NeoTethys as well as compressional tectonics (leading to folding, thrusting, and positive structural inversion) at later times (Coniacian to Recent). This stress history led to the development of fold traps (N-S asymmetric folds in east Arabia and NW-SE folds to the north and east). The local strain associated with the fold/fault structures led to the development of small-throw faults dissecting the fold traps as well as several sets of fractures in the Khuff and other reservoirs. Some of these fractures are related to the regional stress field and others are associated with the folds and/or fault-damage zones. Reactivation of the Permo-Triassic normal faults during later phases of compressional tectonics and development of N-S fault-propagation folds was probably associated with trishear deformation in the steep anticlinal flanks leading to additional fracturing of the rocks.
-