Tengiz oilfield: geological model based on hydrodynamic data

Anissimov, L.; Postnova, E.V.; Merkulov, O.

doi:10.1144/petgeo.6.1.59

Cited by 15 publications

(9 citation statements)

References 4 publications

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“…The deformation mapwhich extends beyond the ENVISAT analysis and covers 79% of the study areaillustrates that the previously recognised subsidence bowl has evolved into a broader region of subsidence that now spans the entirety of the reservoir. In fact, the subsidence has extended by up to 3 km beyond the denoted confines of the platform and rim region and into the flanks on all but the eastern side, which is seemingly bound by northwest-southeast trending faults at this margin (Anissimov et al, 2000). A potential, albeit subtle, northwest-southeast lineament formed by a break-of-slope in the rate of subsidence across strike is somehwhat apparent in this area (Figure 8b).…”

Section: Recent Ground Deformationmentioning

confidence: 86%

“…This represents substantial 6.6-fold and 5-fold increases in subsidence compared to the 2004-2009 period. The greatest increases in subsidence rate are at the northern, eastern and western margins of the field (Figure 9), coinciding with zones of superpermeability (Anissimov et al, 2000). Such areas have been subject to recent field development due to their high fracture densities, making them the highest producing areas in recent years (Collins et al, 2014).…”

Section: Recent Ground Deformationmentioning

confidence: 99%

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Delineating ground deformation over the Tengiz oil field, Kazakhstan, using the Intermittent SBAS (ISBAS) DInSAR algorithm

Grebby

Orynbassarova

Sowter

et al. 2019

International Journal of Applied Earth Observation and Geoinfor

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Changes in subsurface pore pressures and stresses due to the extraction of hydrocarbons often cause deformation over oil and gas fields. This can have significant consequences, including ground subsidence, induced seismicity and well failures. Geodynamic monitoring is an important requirement in recognising potential threats in sufficient time for remedial measures to be implemented. Differential interferometric synthetic aperture radar (DInSAR) is increasingly utilised for monitoring ground deformation over oil and gas reservoirs, achieving greater spatial coverage than traditional field-based surveying techniques. However, ground deformation over oil and gas fields can extend regionally into the surrounding rural landscape, where many conventional DInSAR techniques are of limited use due to the dynamic nature of the land cover. The Intermittent Small Baseline Subset (ISBAS) method is an advanced DInSAR technique, which considers the intermittent nature of coherence over dynamic land cover types to obtain markedly more ground motion measurements in non-urban regions. In this study, the ISBAS technique is used to delineate deformation over the super-giant Tengiz oil field in rural Kazakhstan. Analysis of ENVISAT data for 2004-2009 reveals a well-defined bowl subsiding with a maximum rate of -15.7 mm/year, corroborated by independent DInSAR studies and traditional levelling data. Subsequent application of ISBAS to Sentinel-1 data reveals significant evolution of deformation over the field in 2016-2017, with subsidence increasing dramatically to a maximum of -79.3 mm/year. The increased density of measurements obtained using the ISBAS technique enables accurate and comprehensive delineation and characterisation of ground deformation in this rural landscape, without the need for corner reflectors. This enhanced information could ultimately aid reservoir characterisation and management, and improve understanding of the risk posed by ground subsidence and fault reactivation.

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Section: Recent Ground Deformationmentioning

confidence: 86%

Section: Recent Ground Deformationmentioning

confidence: 99%

Delineating ground deformation over the Tengiz oil field, Kazakhstan, using the Intermittent SBAS (ISBAS) DInSAR algorithm

Grebby

Orynbassarova

Sowter

et al. 2019

International Journal of Applied Earth Observation and Geoinfor

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“…The Tengiz field is located within the seismically active region of Kazakhstan [25]. Existing faulting and erosion at the Tengiz field suggest the possible gravity-driven mass movement of carbonate rocks [26]. Besides the primary man-made oil production factor, the subsidence processes at the Tengiz field are seemingly bound by northwest-southeast trending faults [1,26].…”

Section: Study Areamentioning

confidence: 99%

Quantitative Assessment of Vertical and Horizontal Deformations Derived by 3D and 2D Decompositions of InSAR Line-of-Sight Measurements to Supplement Industry Surveillance Programs in the Tengiz Oilfield (Kazakhstan)

Bayramov

Buchroithner²,

Kada

et al. 2021

Remote Sensing

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This research focused on the quantitative assessment of the surface deformation velocities and rates and their natural and man-made controlling factors at Tengiz Oilfield in Kazakhstan using the Small Baseline Subset remote sensing technique followed by 3D and 2D decompositions and cosine corrections to derive vertical and horizontal movements from line-of-sight (LOS) measurements. In the present research we applied time-series of Sentinel-1 satellite images acquired during 2018–2020. All ground deformation derivatives showed the continuous subsidence at the Tengiz oilfield with increasing velocity. 3D and 2D decompositions of LOS measurements to vertical movement showed that the Tengiz Oil Field 2018–2020 continuously subsided with the maximum annual vertical deformation velocity around 70 mm. Based on the LOS measurements, the maximum annual subsiding velocity was observed to be 60 mm. Cosine corrections of LOS measurements to vertical movement, however, revealed a maximum annual vertical deformation velocity of 77 mm. The vertical deformation confirmed typical patterns of subsidence caused by oil extraction. Detected east-west and north-south horizontal movements at the Tengiz field clearly indicated that the study area crossed by seismic faults is affected by natural tectonic processes. The overall RMSE of 3D decomposed vertical deformation in relationship to LOS measurements and cosine corrections were in the range of 10–13 mm and 6–8 mm, correspondingly. The results of the present research will support operators of oil and gas fields and also other types of infrastructure to evaluate the actual differences of InSAR ground deformation measurements against the required standards and the precision of measurements depending on the operational needs, timeframes and availability of radar imagery.

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“…Over the next 300 million years as burial preceded the temperature rose to 120uC, the d 18 O value of pore water rose to +7%, and salinity increased in proximity to the Triassic salt blanket but was later reduced by intrusion of basinal waters (Anissimov et al 2000).…”

Section: The History Of the Late Visean Parasequencementioning

confidence: 99%

Diagenetic Evolution of Selected Parasequences Across A Carbonate Platform: Late Paleozoic, Tengiz Reservoir, Kazakhstan

Dickson¹,

Kenter²

2014

Journal of Sedimentary Research

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Predicting the diagenetic modification of reservoir quality in carbonate fields is poorly understood but of paramount importance to reservoir characterization. The diagenetic processes and current pore system are reported for two parasequences from the platform center to the margin of the Tengiz reservoir (, 16 km); the late Visean (Lvis13 cbs 900) and Bashkirian (Bash2.5 MSF 350) parasequences are separated by 8 million years.Syndepositional fibrous cement (. 10% rock volume) and aragonite skeletal molds developed in both parasequences. On subaerial exposure, brown soil-related calcite, and meniscus and pendant cements were emplaced in both parasequences.The application of CL petrography to these rocks for the first time has revealed the depositional components and early marine components are altered developing a mottled pattern implying that their original chemistry is not preserved. The principal calcite cement shows a complex growth pattern by CL that is unreported from any other calcite cement. CL is also used to divide the main cement into stage 1, nonluminescent, and stage 2, orange to brown luminescent, calcite. Stage 1 calcite shows vadose meniscus and pendant fabrics followed by uniform phreatic euhedral terminations. Stage 1 cement is patchily distributed at a millimeter scale; 28% to 40% in the Visean and 0.5% to 22% in Bashkirian grainstones. Stage 1 cement is more abundant at the center of the platform in the late Visean than at its margin. Abundant stage 1 calcite creates a framework that prevents later compaction preserving a high porosity at the center of the platform. This sweet spot is reinforced by the deposition of late-stage bitumen cement that occupies 8% rock volume at the margin of the platform but is almost absent at its center. Stage 1 d 13 C values (22.4% to +1.7%) are derived by dissolution of host rock, and their d 18 O values (26.3% to 23.7%) are compatible with precipitation from meteoric or mixed marine-meteoric water.Depositional micrite and micritic grains are transformed by dissolution-precipitation processes into porous microrhombic calcite not by Ostwald ripening. Microrhombic calcite is ubiquitous in the Tengiz icehouse, dispelling the myth that this fabric is restricted to greenhouse epochs.At , 300 million years before significant burial the study grainstones were patchily cemented and dissolved to reach peak porosity; their transformed texture set up flow paths that controlled the distribution of later diagenetic products. Reservoir compartmentalization did not occur through extensive hardground formation at this time as occurs in some greenhouse sequences, but ash bands at parasequence boundaries were turned into tonsteins and wackestones were compacted perhaps sufficiently to influence vertical flow.CL examination of stage 2 calcite that adds 0.5% to 16% to rock volume reveals that its precipitation was episodic and switched sites as the pore network became blocked through precipitation and compaction and was opened by new fractures. A change from acute to equant habit ...

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Tengiz oilfield: geological model based on hydrodynamic data

Cited by 15 publications

References 4 publications

Delineating ground deformation over the Tengiz oil field, Kazakhstan, using the Intermittent SBAS (ISBAS) DInSAR algorithm

Delineating ground deformation over the Tengiz oil field, Kazakhstan, using the Intermittent SBAS (ISBAS) DInSAR algorithm

Quantitative Assessment of Vertical and Horizontal Deformations Derived by 3D and 2D Decompositions of InSAR Line-of-Sight Measurements to Supplement Industry Surveillance Programs in the Tengiz Oilfield (Kazakhstan)

Diagenetic Evolution of Selected Parasequences Across A Carbonate Platform: Late Paleozoic, Tengiz Reservoir, Kazakhstan

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