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IPTC 2014: International Petroleum Technology Conference
- Conference date: 19 Jan 2014 - 22 Jan 2014
- Location: Doha, Qatar
- Published: 19 January 2014
81 - 100 of 354 results
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Greenhouse Gas (GHG) Emission Verification at Ras Laffan City (Case Study)
By A.M. BuhidmaQatar Petroleum is implementing an accurate and auditable procedure for the Accounting & Reporting of Greenhouse Gas (GHG) emissions within Ras Laffan Industrial City (RLC). The procedure is based upon proven European practices and international and industry proven guidelines and methodologies in determining emissions caused by CO2, CH4 & N2O as a result of process combustion, acid gas removal/generation and flaring. Participating companies are all Oil & Gas processing companies and Power and Water Generation companies in RLC with combustion installation having a fuel rated input exceeding 20 MW. Each participating company submits quarterly & annual GHG emissions reports supported with accounting & reporting plan and spreadsheet calculations for verification by an accredited third party verifier hired by Qatar Petroleum. As a result, a Positive Verification Opinion & Statement are issued by the same verifier for each participating company that had proved it’s compliance with the requirements of the applied QP GHG procedure and international guidelines. This paper describes the initiative that Qatar Petroleum deployed in the preparation for the GHG verification process and the implemented methodology in accounting & reporting of GHG emissions at RLC, the achieved progress in uncertainty of the reported GHG data in three consecutive years (2010 – 2012) and the lessons learned for future improvement. The role of Qatar Petroleum in initiating, monitoring & control of GHG emission verification at RLC is also addressed in this paper.
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Improved Statics Model of a Marine 3D Seismic Dataset Through the Application of Refraction Statics Tomography Processing, Offshore Qatar
Authors C. Lange, C. Hanitzsch, M.E. Zahran and G. TylerThis paper describes the refraction statics processing based on tomographic inversion of a 503km2 subset of a modern marine 3D seismic dataset acquired in very shallow waters offshore Qatar. The objective of the seismic survey was imaging of the Mesozoic interval from 0.4 – 1.8 seconds two way travel time below sea level. Characteristic for the study area is the presence of local shoal bodies, often associated with coral reefs at sea bottom and in the near surface below sea bottom. These features can have a significant effect on the imaging of seismic data and therefore the prospectivity assessment of the exploration area as their typically high velocity introduces distortions in the timing of events, i.e. false structures might be generated or true structures suppressed. Compensating for the reef structures in the statics model results in a more accurate image of the subsurface. This was achieved by applying first-arrival travel time tomography to obtain the shallow velocity information needed to calculate refraction statics corrections. Refraction statics tomography uses the first break travel time picks of the seismic data to derive a velocity model of the near surface. This velocity model is then used to generate static shifts to correct the data to a final datum plane using a known replacement velocity, thereby removing the velocity variation caused by the sea bottom and near surface features. The tomographic inversion algorithm for land data was adapted to marine data by including a new option to freeze the water column velocity, which should be constant and not taken into account in the velocity updates. Refraction statics tomography is superior to conventional refraction statics because the inverted velocity model reveals the lateral and vertical velocity variations in the near surface. The dense shot and receiver spacing of this data set provided a large number of first break picks for the tomographic inversion process and resulted in a stable near surface velocity model. The computed static shifts corrected for some of the time shifts observed below the sea bottom features. The application of refraction statics tomography in this study provided an improved subsurface image compared to the original processing.
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Development of an Online, Non-Intrusive Means for Detecting Onset of Formation Water Production in Gas Flow Lines
Authors S.A. Mohammed, M. Aggour, M. Fraim, A. Aboegila, M. Farooqui, H. Al-Kharaz, M. Ashkanani and M. MarmoushProduction of high salinity formation water with gas presents major operational and reservoir management challenges in gas reservoirs. Early detection of unexpected water production is critical for ensuring prompt action to prevent accelerated corrosion damage in surface pipelines and facilities if they are not designed to handle the produced brine. Several methods exist for detecting water in pipelines which are based on electrical, electromagnetic, and acoustic measurements. While most of the existing methods are intrusive requiring direct contact between the measurement probe and the flow stream, all such methods suffer from low accuracy of measurements and dependence on water composition and salinity. This paper reviews the various technologies that are in use to detect and measure water production. It also describes the theoretical background and the laboratory testing of a new means for detecting presence of formation water in gas flow lines.1-10 This work is part of a joint collaboration between RasGas Company Limited and Texas A&M University at Qatar (TAMUQ) aimed at developing a device which is: non-intrusive, clamp-on externally on the flow-line, accurate, and independent of saline water composition. This technology is based on neutron elastic-scattering and activation interactions. The laboratory testing is performed using simulated field conditions to determine the feasibility and accuracy of the measurement technique. Based on the laboratory results, a prototype device is planned to be constructed for field testing. Safety aspects of the process application both in the lab and in the field have been thoroughly examined and comprehensive safety measures have been developed and implemented per the health and safety regulatory requirements. The paper also presents the findings from a simulation study using the Monte Carlo N-Particle (MCNP5) neutron flux simulator11 to examine the feasibility of the proposed method and to properly design and optimize the experimental setup and procedure.
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Diagenetic Geobodies: Fracture-Controlled Burial Dolomite Bodies in Outcrops from Northern Oman
Authors V. Vandeginste, C.M. John and J. BeckertDiagenetic heterogeneities are difficult to predict in subsurface. Nevertheless, such heterogeneities can be crucial in hydrocarbon exploration. Diagenetic processes can significantly alter petrophysical properties of reservoir rocks, especially in carbonate rocks because of the reactive nature of the carbonate minerals. Dolomitization, i.e. the transformation of calcite (limestone) into dolomite, is a common diagenetic process in carbonate rocks. Description: an overview of the learning outcomes gained by studying fracture-related dolomite in outcrops of Oman and subsequent laboratory analysis over the last four years. A combined structural, petrographic and geochemical approach was taken to study three dolomite systems occurring in different stratigraphic host rock intervals. Application: Structurally-controlled dolomitization (i.e. dolomitization along faults and fractures) typically occurs in burial conditions, and the resulting strong permeability anisotropies caused by the dolomite textures can cause major challenges for hydrocarbon exploration. Results and Conclusions: Dolomite bodies in the Precambrian Khufai Formation are related to N-S to NNE-SSW fractures, whereas dolomite bodies that mainly occur in the Jurassic host rocks occur along reactivated WNW-ESE normal faults. These fracture-related dolomite bodies are generally less than 15 m wide, but can be up to a few hundred meters long. Late-diagenetic dolomite bodies were also recognized in Permian host rocks, where they occur at or close to the contact between Permian limestone and early-diagenetic dolomite. This late diagenetic dolomite system can be traced laterally for at least hundreds of meters and occurs in wadi’s about 40 km apart. Our data indicate that there were several dolomitization events in the geological history, generating dolomite bodies with different characteristics. Technical Contributions: This highlights the needs to understand the timing and structural setting of dolomite bodies in subsurface to improve reservoir management.
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Intelligent Wells' Performance and Reliability in the Northern Fields of Saudi Arabia
More LessIntelligent wells have become one of the best-in-class practices in the northern fields of Saudi Aramco with 153 intelligent wells equipped with downhole valve systems completed over the past 10 years. Different service suppliers approached the principle of producing through intelligent wells with their unique actuation mechanism and valve design. Therefore, many trail tests and piloting had been carried out prior to the mass installation of any system to ensure its reliability, functionality and operational suitability. Subsequently, the experiences gained from the operation of the installed intelligent wells over the past decade provided a whole new perspective into their operability, applicability and added value. This paper reflects on the experiences gained from the operation and maintenance of the installed intelligent wells through: * Comparison between the performance of different downhole valve’s actuation mechanisms used in the northern fields of Saudi Arabia with provision of their pros and cons. * Identification of their operational impact and suitability for a specific application environment. * Illustration of their components and the overall system’s reliability with logged surface and subsurface failures along with their impact on the well performance. * Suggestions to select the most appropriate intelligent well system to withstand normal as well as harsh environments while serving the production objectives. The paper also provides valuable recommendations to alleviate the operational and maintenance issues often encountered during the actuation of downhole valves.
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Intelligent-Field Technologies on a Mass Scale: Change for Efficiency Improvement
Authors F.T. Al-Khelaiwi, M.A. Zarea, M.N. Al-Khamis, A.A. Al-Ghamdi and M.A. Al-AmriThe Northern Area Oil Operations of Saudi Aramco has embarked on the installation of Intelligent Field equipment and innovative technologies on a mass scale for the past decade. It was noticed that the initial performance and utilization of such technologies were lower than expected. Therefore; a plan comprised of the following was devised to tackle these deficiencies: 1. Launching a major organizational restructure and assigning a dedicated team of specialists to look after the Intelligent-Field equipment and the real-time data transmission to the databases. 2. Establishing a tailored maintenance service contract with the providers of such technologies. 3. Developing an in-house training program for specialization in the operation, maintenance and utilization of Intelligent-Field equipment. 4. Launching of an innovative technology deployment and evaluation program where each technology is assigned to a technical champion who assumes full responsibility of the technology deployment process. 5. Initiating and maintaining state-of-the-art knowledge management system to track the progress, document the procedures and processes, and capture the lessons learned from the application of each technology. The implementation of these steps resulted in enhanced Intelligent-Field equipment performance efficiency. In addition, the utilization of real-time data — in advanced production and reservoir engineering analysis; such as automated well rate validation and allocation, production optimization and sweep monitoring — has improved due to the high availability and quality of the transmitted data. This paper will provide details of the holistic approach developed by Saudi Aramco for the installation and maintenance of Intelligent-Field equipment and all the implemented changes in the work processes to maximize their performance and tangible benefits. The success and value-added by implementing this generic approach will be illustrated through the high efficiency of Saudi Aramco’s Intelligent-Field equipment, which has been maintained at 99%.
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A Novel Approach to Water-cut Prediction in Deep Cambro-Ordovician Tight reservoir with Complex Hydrocarbon Charge, Diagenetic and Structural Growth Histories
Authors L. Mohsin, S. Al Busaidi, F. Jiroudi and M. Al LawatiIn deep tight shaly-sand reservoir, with complex hydrocarbon charge and structural growth history, it is difficult to characterize reservoir zones with high water cut from others with low water cuts and high hydrocarbon production rate, due to high resistivity readings of tight reservoirs. Deep reservoir “B” in Abu Butabul Field, NW Oman has been charged via two genetically and chronologically different hydrocarbon phases (oil then gas); during a complex deep burial digenesis and structural trap history. Due to the variation of Hydrocarbon properties of such tight reservoir, it has been difficult to analysis such a reservoir using conventional petrophysical evaluation methods. In this study, a modified version of the approach published by Ibrahim, Abd_Elmoula, Said Hasani, Sultan, Jahwari in SPE 130261 in which Ro (Resistivity of Rock saturated with Formation water) and SWirr (irreducible water saturation) used to distinguish water from hydrocarbon zones has been taken a step further in order to predict water cut in tight reservoirs (illustrated in the workflow below). After calculating wireline logs derived permeability, there are two elements to be calculated: KHw (Permeability of sands units filled with water * thickness of these sand units), and KHhc (Permeability of sands units filled with hydrocarbon *thickness of these sand units). The ratio of KHw/(KHhc+KHw) provides a mean of estimating percentage of the expected water production. This approach has been validated with actual water cut from production data. Using mathematical product of KHhc*Phie (effective porosity)*(1-SW) provides a mean to rank the wells in terms of expected Hydrocarbon productivity, which then can be contoured and utilized for reservoir fracturing program of the reservoirs in promising wells. Supporting case-studies and production test results are discussed in order to demonstrate the validity and rate of success of this workflow.Moreover the workflow has been integrated with seismic inversion derived porosity maps in order to delineate areas of larger hydrocarbon reserves, which consequently has obvious implications on reserves evaluation and subsequent field development plan.
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Polymeric Corrosion Inhibitors - a New Class of Versatile Oilfield Formulation Bases
Authors P.-E. Hellberg and A. ZuberbuehlerProduced (oilfield) brines are rich in dissolved salts and thus have high ionic strength as well as conductivity. Further, they are in contact with ferrous metals used for oil- and gasfield installations. Thus, the potential for electro-chemical corrosion reactions in these environments is high. The latent consequences are e.g. general metal wastage, pitting, embrittlement and cracking which all can lead to equipment failure, or even catastrophic results like major oil spills. One of the most abundant methods to mitigate such events is the use of organic corrosion inhibitors (CIs). No doubt, film-forming organic CIs are one of the most important oilfield production chemicals as ranked by volumes used globally. There is a constant need to develop new chemistry in this field, driven by requirements for more environmentally adapted products, lower dosages, higher performance and meeting new compatibility and high temperature/high pressure (HTHP) challenges. The development and testing of of corrosion inhibitors for oil- and gasfield (offshore) use has been thoroughly reviewed (1).
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New Technologies for Optimizing Energy-Fluid Input and Flow Assurance in Mature Assets
Authors J.L. Mogollón, T. Lokhandwala, F. Crespo, C. Hein, S. Rath and L. SayavedraMature fields are the backbone of global oil and gas production. In fact, 70% of worldwide oil production comes from mature fields. A great deal of knowledge about how to exploit mature fields has been gathered throughout the years. However, as more areas become mature, new situations and new challenges arise. Revitalizing these fields extends their productive life and offers significant opportunity to expand worldwide reserves. New technology is critical when trying to increase hydrocarbons extracted from a field beyond the original expectations. This paper highlights emerging techniques associated with five key aspects of revitalizing mature fields. These are: energizing the reservoir using water and polymer flooding on viscous oil fluids, enhancing reservoir deliverability through pinpoint hydraulic fracturing techniques, assuring optimal injectant placement using lasting, functional smart well completions, and improving the rod pumps by using linear lift systems. Also, while technology plays an indispensable role in revitalizing a mature field, cost control, risk management, and optimizing economics are equally important throughout the decision-making process. This paper describes the impact of each emerging mature field technique and discusses recent advancements in technology that enable a new, distinctive approach to increasing production and recovery during the mature stages of the life of a field.
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Elastic Full Waveform Inversion with a Permanent Seismic Source ACROSS: Towards Hydrocarbon Reservoir Monitoring
Authors M. Takanashi, A. Kato, J. Kasahara, S. Luth and C. JuhlinTime-lapse analysis plays an essential role in EOR (enhanced oil recovery) or CCS (carbon capture and storage) management. However, conventional time-lapse seismic often cannot capture differential signals from the target interval because of near-surface heterogeneity or poor signal-to-noise (S/N) ratio. We discuss a potential application of a permanent seismic source “ACROSS” (Accurately Controlled and Routinely Operated Signal System) that can continuously excite controlled seismic signals over years. The superior repeatability of ACROSS makes it possible to subtract any waveforms that do not change over time, and hence the temporal changes due to the fluid replacement at the target interval should be enhanced. Also, it is possible to consider reverse time migration or full waveform inversion rather than just the first arrival or P-wave reflection traveltime inversion, since ACROSS precisely controls the source signature. Both vertical and horizontal single forces are reconstructed by clockwise and counter-clockwise rotations of an asymmetric cylindrical mass. In our synthetic study, we assume that two ACROSS sources are installed at a CO2 pilot injection project in Ketzin, Germany. Elastic FWI (full waveform inversion) is tested with the assumption that the medium parameters (i.e., P- and S- wave velocities and density) before the injection are known. To prevent crosstalk caused by interference of P- and S-waves, we apply a wave separation technique by extracting the scalar (P-wave component) and vector potential (S-wave component) of the elastic wavefields. The simulation results demonstrate that this approach clearly delineates the P-wave velocity decrease caused by the fluid injection. The high-repeatability of ACROSS enables an application of elastic FWI for residual P-wave velocity, which may bring a breakthrough toward CO2 and hydrocarbon reservoir monitoring.
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Reservoir Characterization and Strati-structural Play of Minagish Formation, SE Kuwait
Authors P.K. Nath, S.K. Singh, L. Ye, A. Saleh Al-Ajmi, S.K. Bhukta and A.H. Al-OtaibiThe Middle Minagish (Minagish Oolite) of Berriasian-Valanginian age is oil bearing carbonate reservoir in the Minagish, Umm-Gudair and Burgan fields in Kuwait. This Formation was deposited in an overall eastward-prograding carbonate ramp setting. Spatial variation of lithofacies and reservoir quality such as porosity, permeability and saturation are mainly due to changes in the interplay of deposition, sedimentation and diagenesis within them. The challenge here is to establish a new play concept to ascertain the geometry & nature of reservoir properties in relation to depositional lithofacies in South-East Kuwait. In this study, a systematic approach has been adopted to integrate sedimentology, petrography, petrophysics, sequence stratigaphy and seismic amplitude & attributes to understand reservoir quality and distribution vis-a-vis depositional environment. Ten lithofacies were envisaged from core and petrophysical analysis, out of which peloidal, bioclastic and oolitic grainstone and packstone have good reservoir quality with intraparticle and moldic pores as well as good permeability. A 3rd order Sequence stratigraphic framework was constructed incorporating well and seismic data to identify genetically related reservoir facies and its distribution. A package of forced regression shoal facies is recognized where inner ramp coarse grainstone overlies outer ramp bioturbated pack/wackestone. Seismic amplitude anomaly and waveform facies classification was used to identify lateral facies distribution constrained with conceptual depositional model. 2D seismic inversion was judiciously used to visualize the geometry and spatial distribution of reservoir facies and a new play concept towards north beyond the area of field development. Locally developed shoal in inner ramp and patch reef & reworked carbonate were found to be good locales for porosity development and preservation. The sequence stratigraphic framework shows lateral continuity and cycle of vertical heterogeneity of reservoir architectures .These led to a new play concept of strati-structural play of Minagish Formation towards deep basinal part to the north of SE Kuwait.
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Integrity Management of a Complex LNG Facility
More LessRasGas Company Limited (“RasGas”) employs a Facility Integrity Management System (FIMS) whose primary objective is to create a frame work system to maintain the physical and functional integrity of RasGas critical assets. Programme design starts with grouping equipment by programmes aligned with equipment classes such as structures, pipelines and machinery. Equipment is prioritised by determining its criticality to operations based on health, safety, environment (HSE) and business consequences. Risk-based plans, the so called equipment strategies, are developed to mitigate risks and maintain the desired level of integrity and reliability. These equipment strategy activities are then built into an overall Integrity Programme that includes objectives, roles and responsibilities and practices to ensure operational integrity through the operating life of the equipment. This paper will explain the various aspects and objectives of the system, in particular the benefits of having such a framework in place, managing risk-based inspections, early risk identification, the continuous improvement cycle through data analysis and risk screening non-performed preventive maintenance activities. The Facility Integrity Management System within RasGas would be described with the challenges faced and the lessons learnt during implementation. Challenges in the programme design, development and implementation will be highlighted as well as the strategies and decisions made to overcome these. Particular focus will be given to learnings in the development, implementation and sustainment of equipment strategies, early risk identification and system management.
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Low-Salinity Polymer Flooding: Improving Polymer Flooding Technical Feasibility and Economics by Using Low-Salinity Make-up Brine
Authors E.C.M. Vermolen, M. Pingo-Almada, B.M. Wassing, D.J. Ligthelm and S.K. MasalmehPolymer flooding is a mature EOR technique, which is successfully applied in both sandstone and carbonate reservoirs. In ongoing polymer projects, make-up brine is either formation water, sea water or any available water sources like deep or shallow aquifers. In this paper we focus on the use of low salinity water as the make-up brine. The objectives of combining low salinity flooding (LSF) with polymer flooding are three-fold: • Using low salinity brine reduces the amount of polymer required to obtain the target viscosity, which may lead to significant cost reduction. • Combining the benefit of low salinity flooding with polymer flooding leads to higher oil recovery over conventional polymer flooding. • Enhancing the elasticity of polymers by using low salinity brine which may lead to reduced Sorw and increased oil recovery. In addition to the objectives mentioned above, the use of a low-salinity make-up brine can give other benefits, such as better polymer stability especially at high temperatures), lower sensitivity to polymer shear degradation, lower polymer adsorption and lower scaling and souring tendency. The paper will present 1- Experimental procedures for investigating the potential benefits of low salinity polymer on both the required polymer concentration and the oil recovery. 2- Experimental results for several field cases 3- De-risking activities that were undertaken to mitigate any potential negative impact of using low salinity polymer, in the areas of clay swelling, polymer shear sensitivity, mixing and adsorption. The paper concludes that low-salinity polymer flooding can significantly improve existing and anticipated polymer flooding projects by reducing polymer volumes and/or increasing oil recovery. Low-salinity polymer flooding provides opportunities to apply polymer flooding in high-salinity and high-temperature reservoirs, for which polymer flooding with produced or formation water would be technically unfeasible or uneconomic.
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Nano-Technology for Asphaltenes Inhibition in Cupiagua South Wells
Authors R. Zabala, E. Mora, O.F. Botero, C. Cespedes, L. Guarin, C.A. Franco, F.B. Cortes, J.E. Patino and N. OspinaFormation damage caused by asphaltenes precipitation in Cupiagua south field has a negative impact on the volatile oil production on the wells located in XL pad. Chemical Control of Asphaltenes precipitation has been tested in Cupiagua XL wells to extend the life of organic cleaning jobs. The history of the field shows the usage of diverse commercial asphaltenes inhibitors with organic nature and high aromatic content. Products based on nano technology were tested recently, in which nano-particles of nano-sized metal oxides and high solubility in formation brines are used to adsorb and to carry asphaltenes along the produced oil up to surface avoiding flocculation and precipitation in the reservoir and the near wellbore. In the experimental work, lab tests were run in core plugs taken from the target wells. Results showed ability of nano-fluid to restore the damage caused by asphaltenes; this improved the effective permeability to oil from 5.79 md up to 10.78 md. Lab results also showed as the nano-fluid could reduce the impact on induced precipitation of asphaltenes denoted by the value of effective permeability of 0.09 md oil under non-inhibition had shifted up to 2.54 md where previously 0.3 pore volumes of nano-fluid was squeezed. XL-4 and XL-5 wells were selected for assessing the effectiveness of the nano-fluids to inhibit the precipitation of asphaltenes. The first well cpxl-4 was designed with a volume of 220 barrels of nanofluid to reach 7.2 feet of penetration. The treatment has allowed gains in cumulative production of 118,000 barrels oil after 4 months of squeeze with the nano-fluid. For the second well cpxl-5 the volume of nano-fluid was reduced to 180 barrels and penetration radius was increased to 9.2 feet by using a larger volume of over flush.
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Tectonics of the Mozambique Margin Through the Integration of Gravity and Magnetic Modelling: the Rovuma Basin Case Study
Authors M. Gilardi, R. Longoni and G. SpadiniThe Rovuma Basin is located along the eastern margin of northern Mozambique and southern Tanzania, forming one of a series of continental passive margin basins that stretch along the coast of East Africa. The basin covers onshore and offshore areas for approximately 64,000 Km2. The correct definition of the geological evolution of an area is of primary importance for a proper assessment of its petroleum potential; in the present work an integrated approach, based on seismic interpretation, structural analysis and 2D Gravimetric/Magnetic modelling, has been applied on three different interpreted seismic sections to provide more predictive and reliable geological models. The Gravimetric/Magnetic modelling has contributed to the definition of the Rovuma Basin architecture by testing two possible geological scenarios: one with a shallow top basement surface and another with a deep top basement surface, both interpreted on seismic data. Through the integrated potential methods study one of the above scenarios has been validated. The results of the integrated workflow could be summarized as: - proper basement surface depth scenario definition; - description of the main structural lineament geometries; - basaltic bodies geometry and location definition; - characterization of continental, transitional and oceanic crusts and definition of a possible Continental Ocean Boundary (COB) location. The mutual support between the structural studies and potential method teams has been the key to improve the geological knowledge in frontier exploration areas.
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Satellite Derived Bathymetry and Digital Elevation Models (DEM)
Authors J. Siermann, C. Harvey, G. Morgan and T. HeegeIn 2010, Qatar Shell Upstream International B.V. (QSUI) re-entered Exploration in Qatar focusing on the relatively deep conventional Pre-Khuff gas plays with a view to discover additional hydrocarbons in the State of Qatar. In order to support Qatar Shell with the execution of onshore and offshore seismic programs, satellite imagery was used extensively to derive added value products in terms of shallow water bathymetry, seabed classification and onshore digital elevation models (DEM). For the offshore bathymetry and seabed classification products, 2m resolution multispectral WorldView-2 satellite scenes were processed following a data processing chain including the correction of atmospheric adjacency (increased radiance over water due to reflection of photons by the nearby land and their further scattering in the atmosphere), water surface and water column effects. The resulting offshore products had a spatial resolution of 4m and covered an area of ~700 km2. For the onshore elevation product, a 50cm WorldView-1 stereo image pair was processed using a photogrammetric stereo vision algorithm to generate a 1m spatial resolution DEM over an area of ~450 km2. The accuracy and quality of these satellite image derived products depend largely on the optical conditions of the satellite scene, the sensitivity of the satellite sensor and the accuracy of the calibration. Three types of independent control datasets were used to assess the quality and accuracy of the bathymetry and DEM; airborne LiDAR sounding transects, multibeam echo sounding swaths (offshore) and seismic survey lines (onshore and offshore). After correction for any systematic bias, the correlation of both products with the control data was found to be very good with <1m vertical error in general. Satellite image products are recognized within QSUI as a key technology to aid the planning and preparation of seismic operations and site evaluation by improving hazard identification and reducing field risk exposure early on in the project life cycle. In addition, cost savings were realized compared to more costly traditional acquisition methods. The seismic field conditions were assessed relatively quickly compared to the time frame required for traditional methods. This allowed the data to be included in commercial tendering which in turn resulted in sharper bids. In conclusion, satellite imagery in combination with the right processing techniques has the potential to provide an integrated wide area bathymetry and DEM coverage at relatively high resolution and low cost.
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An Abnormally High Pressure Zone have been Detected to be the Culprit of Many Well Integrity Issues in Dukhan Khuff Wells
By A.A. SultanAn abnormally high pressure formation caused the loss of a number of Dukhan Khuff Gas (DKG) wells. The Sudair formation has always been considered normally pressured throughout the Dukhan Khuff gas field area. However, this case study supports the author’s hypothesis that, contrary to that belief, Sudair can be abnormally pressured. Two DKG wells A and B were the subject of this case study. These wells experienced loss of integrity due to high annuli pressures and were recently worked over. The author’s abnormally high pressure zone hypothesis is based on actual real data from both of these wells. DKG wells were drilled more than thirty years ago. All 28 wells were drilled through the Sudair formation without any pressure or well control issues. However, at some point in time, most of these wells developed annulus pressure in one or more of their annuli. How did that happen? To answer this question, the author searched other operator’s experiences in the area. The search pointed out that the Sudair formation is not always normally pressured; it can also be abnormally pressured. We have seen reports of Sudair high formation pressure associated with high rate salt water flow, high rate gas flow and in occasions very low rate salt water flow. While the high rate flows are detectable, it’s the very low rate high pressure salt water flow that is almost impossible to detect. Another finding is that the Sudair formation pressures are neither equal nor uniform over a large area but rather different and localized. What could we have done differently thirty-five years ago? The answer is simply no thing because we did not have the knowledge and knowhow of today. However, there are lessons to be learnt, t’s to be crossed and i’s to be dotted.
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Multi-agent Collaborative Decision Making for Upstream Asset Management
Authors P. Xu, N. Subrahmanya, A. El-Bakry and C. ReynoldsUpstream assets are very challenging to manage because the components and processes involved are numerous, dynamic, and interdependent. Managing such assets requires execution of multiple technical tasks such as analyzing data, forecasting behavior and optimizing performance. While software tools are available to help engineers perform individual tasks, the goal of integrating cross-functional asset management tasks to achieve a greater level of automation, or even autonomy, remains elusive. As a result, most technical tasks are run and monitored by engineers; and interdependent tasks and cross-functional workflows are integrated through high-level human interaction.
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Magnetic and Gravity Data Acquisition in Deepwater: a new Frontier for the Potential Field Geophysics
Authors G. Gabbriellini, G. Spadini, E. De Marchi, M. Filippini, R. Finotello and D. IndrigoThe O&G industry is moving offshore into increasingly deep waters in order to explore for, develop and exploit hydrocarbon reservoirs in new frontier areas. Standard gravity and magneto-gradiometric acquisitions in such areas are usually performed with ship-borne and airborne techniques. This implies that, especially in ultra-deep waters, the measuring sensors are very far from the geological causative bodies, thus leading to a poor SNR. Eni E&P is committed to adopting and deploying novel proprietary approaches and tools in these challenging environments. As part of an ultra-deep water E&P initiative, Eni and Tecnomare have designed, developed and tested the “AUVG”, a new Autonomous Underwater Vehicle capable of carrying gravimetric and magnetometric instruments onboard for the acquisition of potential field data close to the sea bottom in ultra-deep water environments. The vehicle, which is carried by a supply vessel and launched from it near the area of interest, is autonomously capable of navigating underwater for up to 20 hours, reaching the sea bottom and starting the data acquisition, performing pre-programmed trajectories, avoiding unexpected obstacles, storing the entire data set and emerging in a predetermined position. The vehicle can be located using a radio, strobe lights and a satellite localizer. By means of a Wi-Fi data connection, it is also possible to download data and re-program a new geophysical survey. Gravimetric and magnetometric data acquired by means of an AUV in deep water are characterized by a much higher SNR as well as a higher spatial resolution. These improvements have been experimentally highlighted by a recent test carried out in deep waters in the Ionian Sea.
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Demonstrating the Competence of the Workforce
More LessThe oil and gas industry’s business landscape has changed. The trend is clear: being able to demonstrate the competence of the workforce is now and will continue to be business critical. The argument is simple: just having development programs in place and believing that they equip personnel with the ability to be successful in their job activities, is not enough! It is only when companies assure that all their employees are in fact competent in what they do, that they will deliver on their promises to shareholders, customers, and the community as a whole. Companies have naturally evolved their development methodologies to incorporate a competency program into their business framework. However, in this self-regulated industry not all programs are created equal. This paper describes elements that make up a robust competency program to align with industry practices and regulations. It also describes how a company may demonstrate the competence of its workforce to its stakeholders. The elements that make up a robust program includes: assessing employee’s competence on the job as a preferred methodology; using qualified and competent assessors to conduct assessments; emphasizing employees’ consistency and exposure in the application of the competency; verifying conformance to established processes; and ascertaining the validity and reliability of the competence information. The demonstration requires the company to prove that: it has competency processes in place; it has communicated the processes; and it is applying the processes while developing, assessing, and documenting personnel’s competence. During this demonstration, competence records are shown but the level of detail varies depending on the instance: pre-work, execution of work, and delivery of services. This paper introduces a compelling case for action to assure the competence of the workforce and work towards standardizing an industry-wide approach.
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