Petroleum Development Oman is the major exploration and production company in the Sultanate. It accounts for about 70% of the country's crude-oil production and nearly all of its natural-gas supply. The Company is owned by the Government of Oman , the Shell Group , Total and Partex . Gas fields and processing plants are operated by PDO exclusively on behalf of the Government. Wikipedia.
Warsi M.F.,Islamia University of Bahawalpur |
Shakir I.,King Saud University |
Shahid M.,King Abdullah University of Science and Technology |
Sarfraz M.,King Saud University |
And 2 more authors.
Electrochimica Acta | Year: 2014
High specific capacitance coupled with the ease of large scale production is two desirable characteristics of a potential pseudo-supercapacitor material. In the current study, the uniform and conformal coating of nickel-cobalt layered double hydroxides (CoNi0.5LDH,) nanoflakes on fibrous carbon (FC) cloth has been achieved through cost-effective and scalable chemical precipitation method, followed by a simple heat treatment step. The conformally coated CoNi0.5LDH/FC electrode showed 1.5 times greater specific capacitance compared to the electrodes prepared by conventional non-conformal (drop casting) method of depositing CoNi0.5LDH powder on the carbon microfibers (1938 Fg-1 vs 1292 Fg-1). Further comparison of conformally and non-conformally coated CoNi0.5LDH electrodes showed the rate capability of 79%: 43% capacity retention at 50 Ag-1 and cycling stability 4.6%: 27.9% loss after 3000 cycles respectively. The superior performance of the conformally coated CoNi0.5LDH is mainly due to the reduced internal resistance and fast ionic mobility between electrodes as compared to non-conformally coated electrodes which is evidenced by EIS and CV studies. © 2014 Elsevier Ltd.
Al-Harrasi O.H.,University of Bristol |
Al-Harrasi O.H.,Petroleum Development Oman |
Kendall J.-M.,University of Bristol |
Chapman M.,University of Edinburgh
Geophysical Journal International | Year: 2011
The presence of fractures in hydrocarbon reservoirs can enhance porosity and permeability, and consequently increase production. The use of seismic anisotropy to characterize fracture systems has gained much interest in the last two decades. However, estimating fracture sizes from observations of seismic anisotropy has not been possible. Recent work has shown that frequency-dependent anisotropy (FDA) is very sensitive to the length-scale of the causative mechanism for the anisotropy. In this study, we observe FDA in a microseismic data set acquired from a carbonate gas field in Oman. The frequency-dependent shear wave anisotropy observations are modelled using a poroelastic model, which considers fluid communication between grain size pore spaces and larger scale fractures. A grid search is performed over fracture parameters (radius, density and strike) to find the model that best fits the real data. The results show that fracture size varies from the microscale within the shale cap rocks, to the metre-scale within the gas reservoir, to the centimetre-scale within the non-producing part of the carbonate formation. The lateral variation in fracture density agrees with previous conclusions from ordinary shear wave splitting (SWS) analysis. Cumulatively, the results show the potential for characterizing fracture systems using observations of FDA. © 2011 The Authors Geophysical Journal International © 2011 RAS.
Rameil N.,Ruhr University Bochum |
Rameil N.,Neftex Petroleum Consultants Ltd |
Immenhauser A.,Ruhr University Bochum |
Csoma A.E.,ConocoPhillips |
Warrlich G.,Petroleum Development Oman
Sedimentology | Year: 2012
Discontinuity surfaces in shallow-marine carbonate successions may represent significant time gaps in the geological record of ancient epeiric-neritic seas. Understanding the hidden geological information contained in major discontinuities is thus of key significance in palaeo-environmental analysis, sequence stratigraphy, reconstructions of sea-level change and basin evolution. In the present paper, the Aptian top Lower Shu'aiba Formation discontinuity in the Sultanate of Oman is taken as a prominent example of a regionally extensive (>100000km 2) surface with a long (up to 10Myr) and complex geological history. The top Shu'aiba discontinuity formed on the topographically elevated domain of the Oman platform and represents in essence the Late Aptian time interval. Coeval carbonates in the intrashelf Bab Basin and oceanic rim indicate forced regression and sequence-wise, gradual down-stepping. Available regional, sedimentological, sequence-stratigraphic, petrographic, palaeontological and geochemical evidence from outcrops and cored wells in Oman is summarized, in part complemented by new data, and reviewed in a process-oriented context. In the field, the discontinuity is expressed as a low relief, stained surface with evidence for a marine hardground stage being dominant. Indistinct features that indicate a transient meteoric precursor stage (isotope shifts, meteoric cements, circumgranular cracks, etc.) are present but their interpretation requires careful and detailed work. This feature is remarkable, as a series of relative sea-level falls with amplitudes of up to several tens of metres from the Early to Late Aptian boundary to the end of the Aptian are reported from the Middle East and elsewhere. Despite the palaeogeographic position of the study area in the tropical climate zone, evidence of deep-cutting karst features, characteristic for many long-term exposure surfaces worldwide is scarce. Acknowledging the fact that the modern world offers no genuine analogues for the Lower Aptian carbonate system in Oman, morphological similarities between actualistic, wave-eroded coastal terraces and the top Shu'aiba discontinuity are discussed critically. This discussion may imply that, during an exposure time of several million years, the top Shu'aiba discontinuity experienced repeated stages of shallow flooding and emergence, with each transgression removing portions of the underlying rock record. The data shown here exemplify the complexity of hiatal surfaces in epeiric-neritic carbonates and may serve as a case example for other major discontinuities. © 2011 The Authors. Journal compilation © 2011 International Association of Sedimentologists.
Selden P.A.,University of Kansas |
Selden P.A.,Natural History Museum in London |
Huys R.,Natural History Museum in London |
Stephenson M.H.,British Geological Survey |
And 2 more authors.
Nature Communications | Year: 2010
Copepod crustaceans are extremely abundant but, because of their small size and fragility, they fossilize poorly. Their fossil record consists of one Cretaceous (c. 115 Ma) parasite and a few Miocene (c. 14 Ma) fossils. In this paper, we describe abundant crustacean fragments, including copepods, from a single bitumen clast in a glacial diamictite of late Carboniferous age (c. 303 Ma) from eastern Oman. Geochemistry identifies the source of the bitumen as an oilfield some 100-300 km to the southwest, which is consistent with an ice flow direction from glacial striae. The bitumen likely originated as an oil seep into a subglacial lake. This find extends the fossil record of copepods by some 188 Ma, and of free-living forms by 289 Ma. The copepods include evidence of the extant family Canthocamptidae, believed to have colonized fresh water in Pangaea during Carboniferous times. © 2010 Macmillan Publishers Limited. All rights reserved.
Sanchez F.,Petroleum Development Oman |
Al-Harthy M.H.,Sultan Qaboos University
Journal of Petroleum Science and Engineering | Year: 2011
In today's volatile economy and uncertain drilling environment, managers are encouraged to reduce well cost and time and have implemented Casing-while-Drilling (CwD) to improve operational excellence. Risk analysis is another valid tool that can be used to improve drilling operations. This paper discusses CwD as a new technology and how its benefits can be strengthened by including risk analysis as a complementary technique. A modeling approach is presented to demonstrate how risk analysis can be applied to CwD programs and to discuss the main concerns a well planner must address to achieve a successful drilling program. The integration of both CwD and risk analysis will add value to the overall excellence of the well operation. Very little work has been done on this integration, and the hope is that this approach will be a standard practice in the future. © 2011 Elsevier B.V.