This course provides a fundamental understanding of process safety techniques and how applying these techniques can improve safety, equipment reliability, environmental performance and reduce overall costs. It presents an overview of the elements comprising process safety, practical examples and how process safety can be integrated into day-to-day operations. Working and studying abroad is a huge part of the oil and gas industry and despite the impact on a professional’s career and personal life, little guidance is available for those considering the big move. At this event, we will be sharing stories from those who have gone through the same process and explore some of the benefits and difficulties of diverse working environments. Sustainability means many different things to different people. For governments, it means ensuring development that meets the needs and aspirations of the present without compromising the ability of future generations to meet their own needs.
Africa (Sub-Sahara) Eni successfully completed a new production well in the Vandumbu field, 350 km northwest of Luanda and 130 km west of Soyo, in the West Hub of Block 15/06 offshore Angola. The VAN-102 well is being produced through the N'Goma FPSO and achieved initial production of 13,000 BOED. Production from this well and another well in the Mpungi field will bring Block 15/06 output to 170,000 BOED. Anglo African Oil & Gas encountered oil at the TLP-103C well at its Tilapia license offshore the Republic of Congo. The well intersected the targeted Djeno horizon, and wireline logging confirmed the presence of a 12-m oil column in the Djeno. Total started production from the ultra-deepwater Egina field in approximately 1600 m of water 150 km off the coast of Nigeria. At plateau, the field will produce 200,000 B/D.
The use of Lab NMR, MICP, electrical resistivity measurements and conventional core analysis coupled with petrographic investigations, enabled the authors to understand the pore structure of several carbonate samples and establish a link between pore geometries, Archie's cementation exponent, capillary pressure behavior and NMR T2 response. The lab work was performed on 68 carbonate plugs retrieved from 5 vertical wells completed on a Cretaceous carbonate reservoir, and located at different structural positions (from crest, mid-flank and down-flank areas), capturing different hydrocarbon column heights and, therefore, different degrees of diagenesis and porosity degradation. The equipment used was Magritek 2MHz NMR Rock Analyzer for the T2 distributions, Micromeretics for MICP, Pantera for the ambient resistivity measurements and PORG-200TM for the conventional core analysis. The petrography was done using conventional polarized light microscope. From the combined analysis of NMR T2 spectrum and electrical resistivity measurements we concluded that the magnitude of the Archie's cementation exponent "m" is greater when the samples exhibit variability within the largest pore class ranges (meso to macro scale) than on the smaller pore class range (micro to meso scale).
More than 80% of Abu Dhabi oil reserves are accumulated in the Thamama reservoirs. However, its source rock locations, thickness and richness distributions are not fully understood.
Thamama hydrocarbons were generated and migrated from different source rocks including Diyab, Rayda, Thamama dense and Shuaiba basinal facies, in addition to a contribution from the deeper Paleozoic, Silurian Qusaiba and the Pre-Cambrian Huquf source rocks.
The Oxfordian, Diyab high-energy Oolitic belts are prograding in westward direction, and have resulted in the development of Diyab intrashelf basin in west Abu Dhabi. At the end of the Kimmeridgian time, Abu Dhabi basin was tilted towards the east due to the opening of Arabian-Indian Suture. This tilting had completely shifted the high-energy Oolitic belts to prograde in eastward direction, which resulted in the development of Rayda source rock in east Abu Dhabi.
The Thamama dense layers were deposited during the highstand system tract, which allowed some organic matter to be preserved; especially in intervals deposited below the wave base. The Shuaiba basinal facies were deposited in an intrashelf basin that was surrounded by the Shuaiba shelf facies. This resulted in restricted water circulation and anoxic conditions. Such depositional environment is reasonable for source rock preservation.
The hydrocarbon generations from these different sources were mainly accumulated in a super-giant Paleo-structure that was located in the northeast onshore Abu Dhabi. This Paleo-structure was segmented by the Late Tertiary tilting, which resulted in remigrating its trapped hydrocarbon into the prominent Abu Dhabi fields.
The development of Rayda source rock will increase the potentiality of finding additional unconventional hydrocarbon resources in east onshore Abu Dhabi. The high unconventional potential in this area can be attributed to the advanced level of source rock maturity and to the highly faulting and fracturing found in east onshore Abu Dhabi. The Rayda source rock maturity map confined the unconventional gas potential to the foreland basin while the unconventional oil potential is located to the south of this area (
Understanding the locations of Thamama source rock kitchens will facilitate the delineation of its migration pathways. This will reduce the exploration risk and help in detecting prospective areas for stratigraphic traps potential along the Thamama migration pathways over all Abu Dhabi.
Abu Dhabi Company for Onshore Petroleum Operations (ADCO) HSE policy is fully committed to the principle of sustainability, prevention of pollution, protection of the environment and conservation of natural resources. Thus, It is an important objective for minimum influence on the biodiversity and conservation areas by its operations. Preserving habitats is crucial to any biodiversity action planning strategy within the ADCO Concession Areas. Key habitats are central and indeed survival of many species, including some rare, endangered and protected species. ADCO Operation always care for the natural environment and everything which it contains.
The capacity for the storage of carbon dioxide in saline aquifers remains enormous. Of all geological storage media, it provides the best storage capacity. In this study, the potential of the Shuaiba Formation, in the Falaha syncline, for geologic sequestration is assessed. A regional geo-model was built using seismic and well data (logs, cores) from the Falaha Syncline and nearby fields. The model was built to honor the heterogeneity and sequence stratigraphy of the Shuaiba carbonate platform using a five-order hierarchical conceptual model of the Shuaiba formation that merged sequence architecture and reservoir architecture together. This was achieved by honoring lithofacies, facies association packages and rock types in their corresponding depositional settings in the sequence framework. Dynamic simulations were then conducted on an upscaled geological model using a compositional reservoir simulator to determine its storage and flow capacity, plume migration pathways and to understand the physics of the fluid flow in the aquifer. Simulations are made to be conservative thus accounting for structural/stratigraphic, solubility (dissolution in resident brine) and residual trapping without accounting for the slower mineral trapping process. Detailed sensitivity studies were conducted during the simulations to understand the effect of well parameters, rock and fluid properties amongst others on the storage capacity in the aquifer. Simulation results indicate that significant volumes could be stored in the aquifer and could take a significant amount of time before the injected gas reaches the surrounding hydrocarbon producing fields. This study provides the first full field approach to characterize and to quantify the suitability of the identified aquifer for long term storage of carbon dioxide in the subsurface of UAE.
Oil and Gas world is going through difficult times, with crude prices breaching some of the all-time low values. GASCO believes that, such situations call for extra ordinary efforts to control and extract best results out of every opportunity. Shutdowns/Turnarounds are such cost centric opportunities where careful and controlled actions can have significant effects on company bottom lines. This paper intends to portray the caution, controls and practices during Execution during Asab-0 Turnaround-February 2016, which enabled in producing extra ordinary results for GASCO. GASCO operates its Turnarounds (TA) based on a well-documented'Shutdown Manual', which has strong background in Maintenance Excellence practices on a well-defined process approach. In order to control the TA effectively, Key Result Areas (KRA) were identified and actions were put in place for lean management of the various elements involved. Principles of Systems Dynamics were used to integrate various functions, people and hierarchies to break down silos in communication. Each of the KRA's had elements of this approach in order to achieve performance up-scaling. The KRA's identified were: 1. Cost optimization - achieved through resource optimization (pooling; Seamless integration for optimal use of all available resources (human/equipment)), iterative/dynamic planning, adequate contracting strategy (Performance-based), integrative thinking approach (Minimal Compartmentalization) with stakeholders and early start up.
Naturally, tight carbonate reservoirs exhibit thick transition zones [TZ's] that contain large amounts of oil initially in place [OIIP] and hence significant addition of reserves could be left behind. TZ's are characterized by two-phase flow of both water and oil and there are experimental and field evidences indicating that wettability variation with respect to height above free water level [FWL] is a reality. This variation has to be accounted for in the dynamic model to accurately capture the reservoir performance. However, in real field applications, the situation becomes more complicated while production due to hysteresis effect. To model rock and fluid property [SCAL/PVT] variations across TZ's and its effect on fluid distribution and ultimate oil recovery, a thorough criterion is required to capture all these variations and their interrelationships. This was done by developing a mechanistic flow model using a unique approach to model wettability variation with respect to depth and space, taking into account thick TZ. This is extremely important for all professionals involved in field development activities to better understand the fluid flow behavior of porous carbonates at different heights above the FWL, as a function of oil trapping and rock wettability. The simulation work presented here is a continuation of the research done by Carvalho, Dias et al.  on the behavior of mixed-wet, oil-wet and water-wet systems for a cyclic carbonate reservoir with different rock types.
The significant and continuing loss of mud and/or cement slurry to a formation during drilling operations is one of the most troublesome problems affecting the oil industry. These problems impart a substantial negative impact on well economics.
Loss circulation problems have been identified as one of the most costly and time consuming problems faced in the oil and gas industry. It has been globally estimated that these problems causes drilling industries close to a billion dollars annually in rig time, materials, and other resources.
This paper will describe in detail the nature of the losses and application used to resolve the problem. The use of this unique cement spacer technology is a viable means of resolving most of these problems. This technology, can be applied to strengthen a wellbore, even with when a degree of losses are expected, as a preventive method where fractureing during cementing may occur due to predicted increases in hydrostatics, frictional factors, or both (ECD). In addition, it can also be used as a corrective method in cases where the wellbore is already experiencing losses.
Case histories will be presented describing how this novel spacer cured losses from seepage, moderate, severe and complete loss of returns. The applications include very low fracture gradients wells, where it was impossible to cement with dual slurry with lightweight slurries.
Additional benefits of the spacer is that it is 1) non-damaging, 2) minimizes filtrate invasion from the cement, 3) eliminates or at least drasticly reduces induced losses while cementing, and 4) it forms a permeability barrier membrane on the inside face of the wellbore (Figure 1) wall in-affect strengthening the wellbore allowing successful placement of the cement slurry which in-turn can provide long-term zonal isolation. Formation damage testing with this spacer shows near 100% return permeability.
The spacer rheological can be adjust from low values which minimize increases in ECD to higher YPs as required to enhance mud removal.
Ihab, Tarek (Abu Dhabi Company for Onshore Oil Operations) | Naial, Radwan (ABU DHABI COMPANY FOR ONSHORE OIL OPERATIONS (ADCO)) | Moronkeji, Dee A. (Baker Hughes Inc) | Franquet, Javier A. (Baker Hughes Inc) | Smith, Steven S. (Baker Hughes Inc)
Wireline straddle packer microfrac tests have become an important technology in creating microfractures to measure in-situ formation breakdown pressure, fracture re-opening pressure, fracture closure pressure and stress contrast between reservoir and non-reservoir intervals. The formation tensile strength can also be estimated from the difference between breakdown and re-opening downhole pressures.
This case study describes the use of microfrac tests measurements to validate and calibrate the horizontal stress profile in various intervals of the carbonate reservoir.
Well-injection plans, cap-rock integrity assessment, shale reservoir fracture containment, stress contrast and minimum and maximum horizontal stress estimations can all be quantified from microfrac test measurement.
Six straddle packer stations were tested for microfracturing in this study well. One microfrac test was repeated in one formation due to observed poroelastic effects in the fracture re-opening pressure responses. Poroelastic effects around the borehole occur when the pore pressure near the borehole increases with the injection cycles, thereby making it more difficult to effectively re-open the pre-existing induced fracture. When poroelastic effects are evident, it is important and recommended to record the first pressure fall-off cycle after the formation breakdown for fracture-closure identification. Subsequent cycles will indicate higher fracture closure pressures and therefore overestimate the minimum horizontal stress in the interval.
This paper describes the pre-job modeling, real-time monitoring and post-job interpretation of straddle packer microfrac testing for recalibration of the geomechanical model to provide continuous logs of in-situ horizontal stress profiles over the entire interval.
The well described in this field was drilled in a carbonate reservoir field. It is a new field that is located approximately 260 km south of Abu Dhabi city, and about 80 km southeast of ASAB field. Figure 1 shows the map of this field and the approximate well location. The shallow interval of this field consists of organic rich carbonates because it is in a basinal setting , while the deeper formation is the main oil production formation in onshore Abu Dhabi .
The objective of the microfrac testing was to measure the fracture initiation, propagation, reopening, and closure pressure in various intervals of the carbonate reservoir to validate and calibrate the horizontal stress profile to aid in the study of stress-field anisotropy, the impact of the stress-field on productivity and cap-rock integrity.
The microfrac testing procedure includes formation breakdown, fracture propagation, two fracture reopening cycles, and three pressure fall-off for fracture closure identification. Fracture closure was observed by natural leak-off pressure decline behavior and no flow-back was required to induce fracture closure. Borehole quality is an important factor to consider during the positioning of the wireline straddle packer. The sealing capacity of the inflatable elements against the formation can be compromised by borehole washouts and extensive breakouts . Extreme borehole wall rugosity can also deteriorate the rubber during inflating and deforming the elements. The wireline straddle packer microfrac testing follows the sequence of pre-job assessment, real-time monitoring and post acquisition pressure decline analysis.