Jeff Spath is the nominee for 2014 Society of Petroleum Engineers president. He and nine others make up the slate of nominees recommended for SPE Board positions by the society's Nominating Committee and Board of Directors. These recommendations are based on nominations submitted via SPE's nominating process (see sidebar). Jeff Spath is vice president of industry affairs for Schlumberger, based in Houston. He joined Schlumberger as a well testing field engineer in 1984 and has held various global positions in reservoir engineering, research, and management.
The ALBION project applies a new and disruptive methodology of reservoir characterisation to the carbonate Urgonian Formation (South-East France) considered as the very best analogue of Mid Cretaceous reservoirs from Middle East. Thanks to numerous field sections and outcrops descriptions, to tens of wells drilled in the reservoir, to kilometres of cores, to monitoring of groundwater dynamics such as decades of hydraulic observations at pretty much the only natural outlet of a major groundwater reservoir (Fontaine-de-Vaucluse spring) and to a unique underground laboratory (LSBB, about four kilometers in the heart of the reservoir), a multi-scale model is being built for reservoir purpose. Different observation sites with wells whose spacing ranges from 2 to 20 meters contribute to the assessment of together the matrix, the fractures and the karst flow behaviours. Through the building of an observatory in the heart of a reservoir, the ALBION project is delivering advanced concepts and methodologies to apply to industrial projects in Middle East carbonate fields.
For the last decades, continuous global trend towards more stringent safety, commercial and environmental specifications kept processing sour natural gas containing acid gas such as H2S and/or CO2 a growing challenge. If mercaptans are present in the sour natural gas, the limited mercaptans absorption capacity of the well known alkanolamine solvents can be a major problem. The operating companies have to upgrade their production units to comply with these specification and environmental constraints evolutions. Additional treatment steps are often required to achieve the total sulfur specification in the sales gas, adding process complexity and further increasing cost.
An efficient solution to solve the problem would be to replace the usual alkanolamine aqueous solvent by a hybrid formulation allowing simultaneous removal on mercaptans and acid gases. This approach has been rarely considered because of the side effects of traditional hybrid solvents: hydrocarbon co-absorption, negative impact on the downstream sulfur recovery units. It may be necessary also to replace the internals of the absorber column in the Acid gas Removal Units.
To address this issue, TOTAL is now using a new dedicated hybrid formulation since 2007. This new solvent has been developed by TOTAL by taking advantage of its intensive know-how and experience in gas processing. The hybrid solvent is obtained by addition of a physical component into a generic alkanolamine-water solvent. The final solvent composition is determined to optimize mercaptans removal and minimize hydrocarbon coabsorption, without affecting acid gas removal capabilities.
Without any plant modification, this hybrid solvent can be implemented in existing unit to remove mercaptans with the acid gases, with no detrimental impact on downstream SRU. It allows operating cost reduction of the existing downstream units. Last but not least, the energy consumption of the acid gas removal units can be lowered by 10- 15%.
This paper presents several applications cases where the benefit of using the hybrid solvent is demonstrated.
Periere, Matthieu Deville de (Badley Ashton and Associates Ltd.) | Foote, Alexander (Badley Ashton and Associates Ltd.) | Bertouche, Meriem (Badley Ashton and Associates Ltd.) | Shah, Razza (Al Hosn Gas.) | al-Darmaki, Fatima (Al Hosn Gas.) | Ishaq, Wala bin (Al Hosn Gas.)
The Lower Arab D Member (Kimmeridgian) in onshore UAE is typically characterised by a thick succession of homogeneous mudstones with local cm-scale interbedded bivalve-rich floatstones, which are thought to have been deposited in a low-energy mid-ramp setting. This sedimentological unit is located at the base of a sour gas reservoir that includes the oolitic grainstones of the Upper Arab D Member. The pore system in these micritic deposits is dominated by matrix-hosted microporosity, along with open to partially cemented fractures, primary intraparticle macropores and rare biomoulds in the shell beds, hence a poor to very good porosity and extremely poor to rarely excellent permeability. Variations in porosity and permeability values appear to be strongly related to variations in the micritic fabric: both porosity and permeability increase when the micritic fabric evolves from anhedral compact with coalescent intercrystalline contacts (associated with very little and poorly connected micropores) to subrounded with facial to subpunctic intercrystalline contacts (with locally well-developed micropores). Micritic fabrics also clearly impact the elastic properties of the rock. Through analysis of elastic moduli calculated from standard density, and shear/compressional sonic wireline logs, the relationship between micritic fabric, porosity, permeability and geomechanical properties has been explored.
OMV and ADNOC signed a study agreement in 2013 to explore for hydrocarbons in a large (10,000km2) under-explored onshore area, named East Abu Dhabi. The objective of the work programme was to evaluate the conventional and unconventional hydrocarbon potential within multiple play types and structural settings, via the analysis of existing vintage data, acquisition of new seismic followed by exploration drilling.
To date 1,800km2 3D (4S) and 700km 2D seismic have been acquired focused on two principal play types; namely, the ‘Pabdeh’ stratigraphic play and the ‘Thamama’ combined structural/stratigraphic play. Additional studies completed include fluid inclusion stratigraphy using data from nearby vintage wells, and the completion of an unconventional study covering the wider area of interest. The first OMV operated exploration well reached its TD in the Jurassic in March 2017. Two tests have been performed in Lower Cretaceous and Jurassic resulting in a dry sour gas discovery.
The main results of the well that have an impact on the understanding of the regional geology can be summarized as follows: 1) Source Rock, three potential source rock intervals have been penetrated (Middle and Lower Cretaceous & Jurassic). 2) Reservoir, The middle Cretaceous has been found in a back-shoal facies with its suggested corresponding platform margin being located in close proximity to the South-West. The Aptian is represented by the classical Lower Shuaiba fm. and overlain by the Bab shales. No isolated platform has been encountered. 3) Clear stratigraphic and structural evidence supporting structural deformation of the Thamama Group during the Lower Cretaceous. Several distinct fault trends are evidenced from both the well data and 3D seismic depth slices. Understanding these faults and related fracture systems will be fundamental in understanding the play potential in the wider area.
This is the first exploration well to be drilled in the area since the ‘80s. Multiple intervals of regional interest have been encountered spanning the massive loss circulation intervals of the Palaeocene, conventional and unconventional reservoir within the Middle Cretaceous, the entire Lower Cretaceous sequence and the Asab equivalents of the Upper Jurassic.
The aim of this study is to propose a stratigraphic and sedimentary framework though the integration of available sedimentary, diagenetic and petrophysical data, which will be utilized in the construction of a high resolution stratigraphic framework, as an input into comprehensive review and update of an existing model of heterogeneous carbonate reservoir in a mature field in Abu Dhabi, UAE.
Depositional facies have been defined in cored wells, subsequently were associated taking into account the biologic and sedimentary processes in response of carbonate growing and sea level changes, allowing the identification of the main stratigraphic surfaces.
Surfaces can extend the correlation along the field and define the model of facies that, with the evidence provided by cores, can recreate and predict the different regressive-transgressive cycles in high resolution which the carbonate platform were undergone during its evolution.
Diagenetic evolution, interpreted through laboratory observations, was integrated with facies and petrophysical evaluation allowing the understanding of the spatial distribution of petrophysical properties within a heterogeneous reservoir and define a new set of facies which will be used in the generation of geological static model.
Application of sequence stratigraphy methods in cores, and extended in logs allowed the identification of six depositional sequences, with thicknesses of 2 to 4 meters each, corresponding to the phases of carbonate platform growth. Within each depositional sequences, typical cycles were defined that support the understanding in the association of facies and their relationship during the deposition.
The identification of sedimentological cycles not only genetically organizes the facies and predicts the stacking pattern, but also makes possible to find an excellent correspondence between cycles from lowstand system track intervals with good to excellent permeability values, and cycles from transgressive system track intervals with low permeabilities.
Many of the sequence stratigraphy published articles driven for the most important reservoirs along the Arabian Plate, provide an excellent tool in the regional correlation. However, they are not enough to be used in the reservoir characterization in detail that is required during the development of the field neither as input data in the generation of geological static models that use the sedimentary trends as constrain to populate the petrophysical properties.
Jeong, Jaehoon (ADNOC) | Al-Ali, Abdulla Ali (ADNOC) | Jung, Hyunyoung (ADNOC) | Abdelrahman, Alyazia (ADNOC) | Dhafra, Al (ADNOC) | Shebl, Hesham T. (ADNOC) | Kang, Jeonggil (KADOC) | Bonin, Aurélie (Badley Ashton and Associates Ltd.) | de Perriere, Matthieu Deville (Badley Ashton and Associates Ltd.) | Foote, Alexander (Badley Ashton and Associates Ltd.)
Reservoir quality of carbonate rocks is usually controlled by the interplay of both the primary depositional and secondary diagenetic parameters. The assessment of the respective impact of these controls together with the understanding of the field-scale sedimentological organisation and diagenetic trends assist in the reconstruction of reservoir architecture and help production and appraisal programs. This work focuses on three formations recorded in the onshore Abu Dhabi area with the final aim of understanding their field-scale architecture through the study of six wells. Sediments reflect deposition in clay-prone and cleaner inner ramp to distal mid-ramp, where biotic assemblage is either dominated by
The sedimentological framework has been established through a detailed sedimentological description of
In this area, the depositional fabric is characterised to be the primary parameter on the reservoir properties of the cored Thamama deposits with the exception of the lowermost cored Lekhwair and fractured reservoir: the best reservoir quality is found within inner ramp (locally dominated by
The reservoir architecture will be integrated in the rock typing workflow to assist in the prediction of rock type vertical distribution and their lateral extent.
Nestyagin, Andrey (ADCO) | Al Arfi, Saif (ADCO) | Mostafa, Hassan (Weatherford) | Elkholy, Mohamed (Weatherford) | Fekry, Mohamed (Weatherford) | Awad, Huda (Weatherford) | Mohamed, Omar (Weatherford)
Proper Well Placement in multi layers thin carbonate reservoir could be challenging due to high geological uncertainty. Using radioactive sources to evaluate porosity & formation dipping is effective, but considering the drilling environment & high risk to get stuck makes a lot of restrictions on using of the nuclear tools. This paper is a case study illustrating utilizing absolutely sourceless azimuthal sonic in a comparison with conventional radioactive density as a highly effective alternative sourceless geosteering method & adds extra formation evaluation values. The technique provides azimuthal sonic data were acquired with a focused unipole tool which recorded the measured waveforms and computed Compressional and Shear velocities in 16 azimuthal bins yet Quadrant Compressional and Shear slowness were computed by stacking all 16 bins of data in Realtime, which gave very high signal-to-noise ratios and excellent data quality. The azimuthal Quadrant real-time sonic porosities were effectively used to well placement in the target reservoir, later on the full 16 bin azimuthal memory were examined to understand the additional advantages of using the azimuthal sonic even before approaching the main bed boundaries. Both of Azimuthal Density & Azimuthal Sourceless Sonic measurements were able to detect the boundaries of the target zone, allowing accurate stratigraphic interpretation as well as dip picking calculation to ensure proactive geosteering and maintain the well trajectory as per the plan. It was proven that the Sonic lengthy depth of detection can add an additional safety margin to enable adjusting the well trajectory in the reservoir at the optimal angle, the comparison chanced later against the Azimuthal density image was matching very well and emphasised the formation dipping. This case study proves the capability of using LWD Azimuthal sonic as an effective & alternative sourceless porosity for geosteering and formation dipping calculation purposes.
Vahrenkamp, V. (Abu Dhabi Co For Onshore Petroleum Operation Ltd) | Franco, B. J. (Abu Dhabi Co For Onshore Petroleum Operation Ltd) | Popa, D. (Abu Dhabi Co For Onshore Petroleum Operation Ltd) | Barata, J. (Abu Dhabi Co For Onshore Petroleum Operation Ltd) | Grelaud, C. (University Of Bordeaux) | Razin, P. (University Of Bordeaux) | Grosheny, D. (Université de Strasbourg) | Bulot, L. (Aix-Marseille Université, UMR)
The Upper Cretaceous Shilaif intra-shelf basin at the eastern margin of the Arabian platform contains rich source rock sequences in the hydrocarbon generation window, which are targets for ongoing exploration work. Time stratigraphy and sedimentology are key components to unravel the complex development of the hydrocarbon system. This paper presents detailed bio-, chemo- and sequence-stratigraphic data in combination with sedimentological analysis from core, well, seismic and outcrop data to support an analysis of basin architecture and regional time stratigraphic correlations.
The Late Albian to Turonian saw the final intra-shelf basin development and infill on the eastern margin of the Arabian plate Cretaceous carbonate platform. Basin development began with the deposition of the Late Albian Mauddud Formation. Mauddud cycles are laterally continuous over large distances but thin in western and central Abu Dhabi in the area of the future intra-shelf basin. Differential aggradation is likely to have been accentuated by unfavorable climatic and water-quality conditions related to the Albian/Cenomanian Oceanic Anoxic Event.
The Mauddud is overlain in the west and east of Abu Dhabi by the shallow marine aggrading & prograding carbonates of the Mishrif Formation with a SSW-NNE elongated intrashelf basin forming in central Abu Dhabi. This basin is filled by the Shilaif, Tuwayil and Ruwaydah Formations. Four depositional sequences with organic rich intervals are recognized in the Shilaif Fm corresponding in time to pulses of aggradation, progradation and retrogradation of Mishrif shallow-water platform margin sediments.
The Tuwayil is a shaly lowstand/transgressional sequence onlapping onto the Mishrif, which was at this time partially exposed based on erosional channel incisions on the platform top. The Ruwaydah Fm is composed significantly of calcispheres recording continued transgression, increased accomodation space and an increase of carbonate production. The Coniacian Laffan shales unconformably overlie the Cenomanian/Turonian sedimentary sequences.
Basin-fill sequences have been age dated with detailed chemo- and biostratigraphy. Based on carbon isotopes the Mauddud predates/coincides with the OAE at the Albian/Cenomanian boundary and is hence late Albian. Other carbon peaks, ammonites, calcispheres and planktonic foraminifera align the Shilaif with the Cenomanian reaching near its top the Cenomanian/Turonian boundary. The Tuwayil and Ruwaydah Fms are Turonian.
Vahrenkamp, Volker C. (ADCO) | Van Laer, Pierre (ADCO) | Franco, Bernardo (ADCO) | Celentano, Maria Agustina (ADCO) | Grelaud, Carine (University of Bordeaux) | Razin, Philippe (University of Bordeaux)
The occurrence of major hydrocarbon prone Mesozoic source rock sequences of the eastern Arabian plate is directly tied to the generation of intra-shelf basins within the giant carbonate platforms that formed during this time period. This paper investigates the driving forces behind the formation of intra-shelf basins and related source-rock/seal sequences. Results impact topics such as exploration, reservoir distribution, regional tectonics and climate modelling.
A combination of large scale regional stratigraphic correlations, age dating, geochemical indicators and global climatic/tectonic events are investigated to explain differences and commonalities in basin formation and their impact on source rock seal pairs.
In the Mesozoic major intra-shelf basins existed during three time periods: in the Late Jurassic during the Oxfordian to Tithonian, and in the Cretaceous during the Aptian and the Cenomanian.
The late Jurassic basin is predominantly generated by plate margin tectonism possibly in conjunction with the rejuvenation of major WNW-ESE and N-S basement structures. Uplift at the eastern plate margin during the late Jurassic caused exposure at the eastern plate margin towards the Neo-Tethys, which in combination with sea level fluctuations resulted in the deposition of several large scale cycles. In central Abu Dhabi westward progradation of the Tuwaiq Mountain, Hanifa and Jubaila Sequences into an intrashelf basin are key evidence for the eastern uplift as are large scale collapse features reported from the eastern margin itself. The widespread deposition of the Arab and Hith anhydrites in the interior of the eastern Arabian plate are taken as further evidence for tectonically driven basin isolation leading to restricted evaporitic conditions.
In contrast, the Cretaceous Aptian and Cenomanian intra-shelf basins formed mainly as a consequence of environmental/climatic disturbances associated with global oceanic anoxic events. During these times of global climate stress carbonate sedimentation was unable to keep up in areas with relatively high subsidence rates and laterally segregated providing the impulse for a switch from flat-topped platforms to a nascent basin topography (Hawar & Thamama A/Shuaiba during the latest Bar/Early Aptian; AP Apt 1), and Mauddud FM (latest Albian). Subsequent differential aggradation in combination with continued subsidence led to the full development of the basin topography in the early Aptian (AP Apt2–4; Bab Basin) and early Cenomanian (Shilaif Basin). Significantly, detailed carbon isotopic data indicate that climatic disturbances and the onset of oceanic anoxic events correspond to the generation of the initial topography and not to the onset of the deposition of organic rich basin fill sediments. Subsequent to deposition of organic rich sequences Cretaceous intra-shelf basins are dominated by argillaceous limestones and siliciclastics (Bab basin: Upper Bab Member - AP Apt5 and basal Nahr Umr AP-Apt6; Shilaif Basin: lower & upper Tuwayil FM).
Thus, basin fill differs significantly between the late Jurassic tectonic basin featuring evaporate seals (Arab and Hith FM) and the Cretaceous climatic/constructional intrashelf basins being covered by clastic-rich sequences.
Finally, it is postulated that the formation of another intra-shelf basin associated with the Valenginian Oceanic Anoxic Event (OAE1) was prevented by a regional tectonic uplift and platform exposure during the Late Valenginian.