Relation between hydrocarbon saturation and pore pressure evaluation for the Amal Field area, Gulf of Suez, Egypt

Abstract Optimizing the number of casing strings has a direct impact on cost of drilling a well. The objective of the case study presented in this paper is the demonstration of reducing cost through integration of data. This paper shows the impact of high-resolution 3D geomechanical modeling on well cost optimization for the GS327 Oil field. The field is located in the Sothern Gulf of Suez basin and has been developed by 20 wells The conventional casing design in the field included three sections. In this mature field, especially with the challenge of reducing production cost, it is imperative to look for opportunites to optimize cost in drilling new wells to sustain ptoduction. 3D geomechanics is crucial for such cases in order to optimize the cost per barrel at the same time help to drill new wells safely. An old wellbore stability study did not support the decision-maker to merge any hole sections. However, there was not geomechanics-related problems recorded during the drilling the drilling of different mud weights. In this study, a 3D geomechanical model was developed and the new mud weight calculations positively affected the casing design for two new wells. The cost optimization will be useful for any future wells to be drilled in this area. This study documents how a 3D geomechanical model helped in the successful delivery of objectives (guided by an understanding of pore pressure and rock properties) through revision of mud weight window calculations that helped in optimizing the casing design and eliminate the need for an intermediate casing. This study reveals that the new calculated pore pressure in the GS327 field is predominantly hydrostatic with a minor decline in the reservoir pressure. In addition, rock strength of the shale is moderately high and nearly homogeneous, which helped in achieving a new casing design for the last two drilled wells in the field.

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Stress Path Analysis of the Depleted Middle Miocene Clastic Reservoirs in the Badri Field, Gulf of Suez Rift Basin, Egypt

10.2118/205900-ms ◽

2021 ◽

Author(s):

Ahmed E. Radwan ◽

Souvik Sen

Keyword(s):

Path Analysis ◽

Pore Pressure ◽

Middle Miocene ◽

Stress Path ◽

Horizontal Stress ◽

Gulf Of Suez ◽

Normal Faulting ◽

Future Production ◽

Uniaxial Compaction ◽

Rate Optimization

Abstract The purpose of this study is to evaluate the reservoir geomechanics and stress path values of the depleted Miocene sandstone reservoirs of the Badri field, Gulf of Suez Basin, in order to understand the production-induced normal faulting potential in these depleted reservoirs. We interpreted the magnitudes of pore pressure (PP), vertical stress (Sv), and minimum horizontal stress (Shmin) of the syn-rift and post-rift sedimentary sequences encountered in the studied field, as well as we validated the geomechanical characteristics with subsurface measurements (i.e. leak-off test (LOT), and modular dynamic tests) (MDT). Stress path (ΔPP/ΔShmin) was modeled considering a pore pressure-horizontal stress coupling in an uniaxial compaction environment. Due to prolonged production, The Middle Miocene Hammam Faraun (HF) and Kareem reservoirs have been depleted by 950-1000 PSI and 1070-1200 PSI, respectively, with current 0.27-0.30 PSI/feet PP gradients as interpreted from initial and latest downhole measurements. Following the poroelastic approach, reduction in Shmin is assessed and reservoir stress paths values of 0.54 and 0.59 are inferred in the HF and Kareem sandstones, respectively. As a result, the current rate of depletion for both Miocene reservoirs indicates that reservoir conditions are stable in terms of production-induced normal faulting. Although future production years should be paid more attention. Accelerated depletion rate could have compelled the reservoirs stress path values to the critical level, resulting in depletion-induced reservoir instability. The operator could benefit from stress path analysis in future planning of infill well drilling and production rate optimization without causing reservoir damage or instability.

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Modeling pore pressure and fracture pressure using integrated well logging, drilling based interpretations and reservoir data in the Giant El Morgan oil Field, Gulf of Suez, Egypt

Journal of African Earth Sciences ◽

10.1016/j.jafrearsci.2021.104165 ◽

2021 ◽

pp. 104165

Author(s):

Ahmed E. Radwan

Keyword(s):

Pore Pressure ◽

Well Logging ◽

Oil Field ◽

Gulf Of Suez ◽

Fracture Pressure

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Exploiting Slim Pulsed Neutron Spectroscopy for Unlocking Reservoir Potential in Brownfields: Two Examples from Gulf of Suez Offshore Field in Egypt

10.2118/204751-ms ◽

2021 ◽

Author(s):

Mohamed Ameen ◽

Eslam Atwa ◽

Youssif Youssif ◽

Emad Abdel Hakim ◽

Mohamed Farouk ◽

...

Keyword(s):

Integrated Approach ◽

Carbonate Reservoir ◽

Advanced Technology ◽

Gulf Of Suez ◽

Neutron Spectroscopy ◽

Fluid Saturation ◽

Crucial Information ◽

Hydrocarbon Saturation ◽

Cement Integrity ◽

Pulsed Neutron

Abstract For more than 40 years, pulsed neutron spectroscopy has been primarily used in reservoir management to determine hydrocarbon saturation profiles, tracking reservoir depletion, and planning workover activities to diagnose production problems such as water influx. Legacy pulsed neutron tools used to provide this information for more than four decades, but they were challenged when a mixed lithology reservoir is encountered, complex completions, unknown borehole conditions, and poor cement integrity in cased boreholes. This paper presents two successful field examples and applications using the advanced slim pulsed neutron spectroscopy to precisely determine multiphase contacts in a complex geological structure, provide current hydrocarbon saturation independent of the quality of cement behind the casing, and identifying bypassed hydrocarbon. This was of paramount importance in understanding current reservoir fluid distribution to reveal the true potential of this offshore brownfield located in the Gulf of Suez, Egypt. An integrated approach and candidate well selection were done that resulted in selecting two candidate wells that had poor cement quality behind casing, heterogeneous carbonate reservoir with mixed lithology, and uncertain fluid contacts in a complex reservoir structure. These combined borehole and reservoir conditions resemble challenges for capturing this crucial information with high confidence using the legacy pulsed neutron tool, and therefore required an advanced technology that can overcome these challenges using a single logging mode at twice the logging speed of any current pulsed neutron technology available in the industry. Based on the results, a workover campaign was implemented in this mature field to increase overall oil production with very efficient cost control, especially with this unprecedented time the O&G industry is going through. An integrated approach was set that resulted in the selection of two wells for the saturation determination logging tool deployment. Detailed high-resolution mineralogy, self-compensated total porosity and sigma, fluid type identification, and multiphase fluid saturation was obtained with high precision behind cased borehole independent of cement integrity and borehole fluid reinvasion. The results provided crucial information as an input to the integrated reservoir engineering approach which revealed around a 100-m net oil interval which was previously overlooked due to relatively low resistivity. Besides, fluids contacts were evaluated that confirmed the development of a secondary gas cap and the water encroachment direction. This technology can be further applied to more brownfields provided the right candidate selection is done to understand the potentiality of the field which would increase the recovery factor of the brownfields that represent almost more than 65% of the oil and gas fields around the world.

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Integration of geophysical and geomechanical data to understand the depletion of the Marlim field, Campos Basin

Geologia USP Série Científica ◽

10.11606/issn.2316-9095.v21-166922 ◽

2021 ◽

Vol 21 (1) ◽

pp. 45-55

Author(s):

Larissa Furtado Torres ◽

Emílio Velloso Barroso

Keyword(s):

Pore Pressure ◽

3D Models ◽

Pressure Gradients ◽

Campos Basin ◽

Sea Level Variations ◽

Pore Pressure Gradient ◽

4D Seismic ◽

Seismic Anomalies ◽

Potential Fluid ◽

Field Area

Located in the Campos Basin, Brazil, the Marlim field, consists of two turbidite systems deposited during eustatic sea-level variations in the Oligocene/Miocene. The reservoir was discovered in 1985, and its production started to decline in 2002. One of the techniques selected to assist in the recovery of oil from the reservoir was the 4D seismic. However, its interpretation can be complex. In order to help address this issue, the present study proposed an analysis of the depletion of a small field area from 1997 to 2010, combining geophysical (4D seismic) and geomechanical (pore pressure) data through the construction of pore pressure 3D models for both years, which can be subtracted and compared to seismic anomalies. The results obtained were: an average depletion of 0.42 ppg (50.33 kg/m3) of pore pressure gradient in the field; the identification of potential fluid-flow barriers, such as an NW-SE-oriented channel and sealing faults; and the detection of two areas with an expressive presence of 4D seismic anomalies, one of them showing a quite evident difference between pore pressure gradients, suggesting field depletion. The use of very old and noisy seismic data hindered the application of this methodology. Nevertheless, this research demonstrated the relevance of estimating pore pressure in the reservoir and how this geomechanical parameter can be useful in assessing the level of field depletion.

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