Integration Of Seismic Data Research Articles

Enhanced Prospect Definition Using Well and 4D Seismic Data in a Niger Delta Field

We carried out time-lapse analysis in a producing Niger Delta X-field, by first investigating the response and sensitivity of rock properties/attributes to lithology and pore fill in 3-D cross plot domain and by Gassmann’s fluid substitution modeling. Furthermore, 4-D seismic data were inverted into acoustic impedance volumes through model based inversion scheme. This served as input into a multi-attribute neural network algorithm for the extraction of rock attribute volumes based on the results of the petrophysical log analysis. Subsequently, horizon slices of rock properties/ attributes were extracted from the inverted seismic data and analyzed. In this way, we mapped hydrocarbon depleted wells in the field, and identified probable by-passed hydrocarbon zones. Thus, the integration of well and time lapse seismic (4-D) data in reservoir studies has remarkably improved information on the reservoir economic potential, and enhanced hydrocarbon recovery factor.

Integrating 3D seismic data and hydraulic units to improve reservoir property models

SUMMARY We present a new method for reservoir property modeling based on integration of 3D seismic data and hydraulic flow units, and apply it to an example of a producing reservoir offshore Western Australia. Our method combines hydraulic unit analysis with a set of techniques for seismic reservoir characterization including: rock physics analysis, Bayesian inference, pre-stack seismic inversion and geostatistical simulation of reservoir properties. Hydraulic units characterize regions and properties of fluid flow in porous permeable media, and are defined at well locations. However, usually the number of wells and their lateral coverage is extremely limited. In contrast, the lateral resolution of 3D seismic data is excellent, and this can be used to extend hydraulic unit analysis away from well locations into the 3D reservoir volume. We develop a probabilistic relationship between each of the hydraulic units defined at well locations, and the 3D seismic information. Reservoir models jointly constrained by 3D seismic and hydraulic unit analysis can therefore be useful to improve the production history matching process.

Integration of completion data, microseismic data, downhole logs, and multicomponent seismic data in the Mississippi Lime, north-central Oklahoma

Previously published work on a Mississippi Limestone (Mississippi Lime) prospect in north-central Oklahoma described a prospect that is data rich. Aquisition was on a dense grid using nodal 3C phones, and PP and PS data were both processed and jointly inverted. Several pilot holes and laterals were drilled and fully logged, including Sonic Scanner and formation-microimager (FMI) fracture logs. Microseismic data were acquired on one well pad, as was a 3D VSP. New resesarch discusses two specific fracture-characterization methodologies. The first is the integration of vertical and lateral log suites, including fracture imaging, with seismic rock properties and completion results, including microseismic data. The results of this effort not only characterize fracture width and height but go farther by explaining why and how those fractures are created. The second is the use of converted-shear (PS) data to measure anisotropy and correlate those measurements with fracture logs. Specifically, two methods of calculating anisotropy are analyzed: slow shear-wave (S2) traveltime correction and transverse/radial energy ratio. Both methods are theoretically valid but might break down in practice because of various nongeologic artifacts that can be present in the data.

Unconventional resource evaluation and applied geophysics utilising LMR

Over the last decade the oil and gas industry has delivered conceptual and technical changes that have entirely changed the fundamentals of natural gas supply in North America. Underpinning the step change in natural gas reserves and market ready supplies has been the change in the perception of fine-grained, organic rich rocks (i.e. shales – although of course not all shales are organic rich). No longer are such rocks viewed only as source and seal candidates, but also as source rock reservoirs or shale gas plays. Although the geological continuity of shale gas plays have led to the production-line style operations seen across North America in mature unconventional plays, it is not factory-style efficiency improvements in isolation that allow the economic exploitation of shale gas. The large number of fit-for-purpose technologies, introduced by operators and service companies, has been critical in increasing production while keeping costs flat and/or reducing costs and time to production. 3D seismic data play a key role in unconventional developments as a unique look-ahead dataset. The role of seismic, however, has evolved to be far more than simply a tool for mapping major structures. For example, through AVO inversion we are able to make predictions regarding elastic properties of the formations of interest. The integration of AVO inversion data with engineering and rock physics data is providing new avenues of data exploitation. Seismic data are also being used to predict closure stress and stress anisotropy, which can be calibrated with data and analysis from hydraulic fracturing. Additionally, the integration of surface seismic data with microseismic provides a means of fine-tuning the estimation of stimulated rock volume.

Integration of seismic and gravity data — A case study from the western Gulf of Mexico

A 3D gravity model was developed in the western Gulf of Mexico in the East Breaks and Alaminos Canyon protraction areas. This model integrated 3D seismic, gravity, and well data; it was constructed in support of a proprietary seismic reprocessing project and was updated iteratively with seismic. The gravity model was built from seismic horizons of the bathymetry, salt layers, and the acoustic basement; however, the latter was only possible to map in seismic data during the latest iterations. In addition, a deep layer representing the Moho boundary was derived from gravity and constrained by public-domain refraction data. A 3D density distribution was derived from the seismic velocity volume using a modified Gardner equation. The modification comprised imposing a depth dependency on the Gardner coefficient, which is constant in the classic Gardner equation. The modified coefficient was derived from well data in the study area and public-domain velocity-density data sets. The forward-calculated gravity response of the composed density model was then compared with the observed gravity field, and the mismatch was analyzed jointly by a seismic interpreter and a gravity modeler. Adjustments were then made to the gravity model to ensure that the resultant salt model was geologically reasonable and supported by gravity, seismic, and well data sets. The output of the gravity modeling was subsequently applied to the next phase of seismic processing. Overall, this integration resulted in a more robust salt model, which has led to significant improvements in subsalt seismic imaging. The analysis of the regional trend in the observed gravity field suggested that a stretched continental crust underlay our seismic reprocessing area, with an oceanic-continental transition zone located to the southeast of our reprocessing region.

The integration of gravity, magnetic and seismic data in delineating the sedimentary basins of northern Sinai and deducing their structural controls

The Sinai Peninsula is a part of the Sinai sub-plate that located between the southeast Nubian–Arabian shield and the southeastern Mediterranean northward. The main objectives of this investigation are to deduce the main sedimentary basin and its subdivisions, identify the subsurface structural framework that affects the study area and determine the thickness of sedimentary cover of the basement surface. The total intensity magnetic map, Bouguer gravity map and seismic data were used to achieve the study aims. Structural interpretation of the gravity and magnetic data were done by applying advanced processing techniques. These techniques include; Reduce to the pole (RTP), Power spectrum, Tile derivative and Analytical Signal techniques were applied on gravity and magnetic data. Two dimensional gravity and magnetic modeling and interpretation of seismic sections were done to determine the thickness of sedimentary cover of the study area. The integration of our interpretation suggests that, the northern Sinai area consists of elongated troughs that contain many high structural trends. Four major structural trends have been identified, that, reflecting the influence of district regional tectonic movements. These trends are: (1) NE–SW trend; (2) NNW–SSE trend; (3) ENE–WSW trend and (4) WNW–ESE trend. There are also many minor trends, E–W, NW–SE and N–S structural trends. The main sedimentary basin of North Sinai is divided into four sub-basins; (1) Northern Maghara; (2) Northeastern Sinai; (3) Northwestern Sinai and (4) Central Sinai basin. The sedimentary cover ranges between 2km and 7km in the northern part of the study area.

Korelasi Data Log Sumur dan Seismik untuk Penyebaran Litologi dan Porositas Reservoir Hidrokarbon Formasi Gumai Cekungan Sumatera Selatan

Integration of seismic data and well log is carried on the field X to identify the distribution of lithology and porosity in the reservoir target zone in this field. With the purpose to get a good interpretation of the subsurface in the process of hydrocarbon exploration. The integration of data is done by using acoustic impedance inversion analysis. Two types of acoustic impedance inversion method is applied to the well log data and seismic, i.e maximum likelihood sparse spike and a model-based inversion. Both of them have a high correlation coefficient and a low error rate. Sparse spike inversion result was selected to use in the next process as it has an acoustic impedance value that is more similar to the well log acoustic impedance value. Acoustic impedance models correlated with the lithological profiles of well log is used to predict the spread of reservoir lithology. Sparse spike inversion results are then used as input to the module EMERGE on Hampson Russell Suite 9 software, to predict the distribution of porosity from seismic volume. The volume of porosity is determined from regression function crossplot between acoustic impedance inversion results with fixed porosity well logs.

3D seismic interpretation of the depositional morphology of the Middle to Late Triassic fluvial system in Eastern Hammerfest Basin, Barents Sea

Integration of seismic, well and outcrop analog data provided realistic definition of the depositional morphology of the Snadd Formation in the Eastern Hammerfest Basin, Barents Sea. In this work the morphology of the depositional system was analyzed by using acoustic impedance seismic attribute on a high-resolution 3D seismic data. Five horizon slices were interpreted between the Snadd and Fruholmen Formation. Information about lithology and environment of deposition was inferred from wireline logs and by correlation to analogs of the De Geerdalen Formation in Spitsbergen and Snadd Formation in the NE Barents Sea. The Middle to Late Triassic sediments in the study area were deposited by a meandering fluvial system characterized by depositional forms such as flood plains, point bars, levees, overbank deposits and crevasse splays. In the southwest and the northeastern part of the seismic cube, the meandering channel is divided into low and high sinuosity channels, respectively. Sinuosity of the channel is related to the paleo topography of the Middle Triassic unit (S2) with sediment source area and flow direction being from the higher areas in the southwest to low areas in the northeast. This work shows that the Middle to Late Triassic sediments in the study area were possibly sourced from the southwestern part of the present-day Barents Sea in regions correlated to the Baltic and Uralian highs.

Active tectonics of western Potwar Plateau–Salt Range, northern Pakistan from InSAR observations and seismic imaging

The foreland fold-and-thrust belt of northern Pakistan is located at the western end of the Himalayan arc, where salt tectonics is responsible for structural styles, hydrocarbon source areas and seismicity. Three sub-regions of fold-and-thrust belt are the Potwar Plateau–Salt Range, Kohat Plateau–Surghar Range and the Bannu Basin–Khisor Range. The difference in deformation intensity between these regions is mainly attributed to the presence, or absence, of an Infra-Cambrian salt layer. This study investigates the active tectonics of the Potwar Plateau and Salt Range region, emphasizing the role of salt, using the Small Baseline Subset Interferometry (SBAS) technique and 2-D seismic interpretations. Ten PALSAR images and four seismic profiles from western Potwar Plateau–Salt Range region were used. SBAS results, derived from PALSAR images spanning from 2007 to 2010, suggest that the Potwar Plateau–Salt Range is active with the western portion of the region experiencing an uplift at an average rate of around 10 mm/year. Two uplift anomalies were observed, which were interpreted as zones of transpression and salt diapirism. Time-migrated seismic profiles show that the salt layer acts as a detachment. Our results show that salt has different roles in different regions of the fold-and-thrust belt; in the Potwar Plateau region the salt layer acts as a detachment, while in Salt Range salt flow-induced structures are prominent. The integration of SBAS and 2D seismic interpretation reveals that the deformation of western Potwar Plateau–Salt Range is influenced by two main faults, the dextral Kalabagh fault and the Main Frontal Thrust. Finally, this work was compared to the Kuqa fold-and-thrust belt in western China due to their structural similarities. • Salt acts as a detachment in Potwar and salt diapirism is prominent in Salt Range. • Integration of InSAR and seismic data helped to map the deformation in this region. • InSAR data from 2007–2010 suggests that Salt Range underwent uplift up to 15 mm/year. • Uplifted zones from the InSAR data were related to transpression and salt diapirism. • Differential loading may be the main driving force for the salt moving to the south.

Enhanced heavy oil recovery for carbonate reservoirs integrating cross-well seismic – A synthetic Wafra case study

Abstract Heavy oil recovery has been a major focus in the oil and gas industry to counter the rapid depletion of conventional reservoirs. Various techniques for enhancing the recovery of heavy oil were developed and pilot-tested, with steam drive techniques proven in most circumstances to be successful and economically viable. The Wafra field in Saudi Arabia is at the forefront of utilizing steam recovery for carbonate heavy oil reservoirs in the Middle East. With growing injection volumes, tracking the steam evolution within the reservoir and characterizing the formation, especially in terms of its porosity and permeability heterogeneity, are key objectives for sound economic decisions and enhanced production forecasts. We have developed an integrated reservoir history matching framework using ensemble based techniques incorporating seismic data for enhancing reservoir characterization and improving history matches. Examining the performance on a synthetic field study of the Wafra field, we could demonstrate the improved characterization of the reservoir formation, determining more accurately the position of the steam chambers and obtaining more reliable forecasts of the reservoir’s recovery potential. History matching results are fairly robust even for noise levels up to 30%. The results demonstrate the potential of the integration of full-waveform seismic data for steam drive reservoir characterization and increased recovery efficiency.

Integration of Petrophysical and Seismic Data to Construct a Reservoir Permeability Model

This article demonstrates how to model permeability in different levels of a reservoir, integrating petrophysical and seismic data. In the first part of the present study seismic data is interpreted, including horizon and fault interpretations. Based on this, a reliable structural model of the prospect is built. In the second part, three common geostatistical techniques (including kriging, sequential Gaussian simulation, and collocated co-simulation) are employed to distribute permeability over the studied area such that it realistically preserves the reservoir heterogeneity and matches the well data. Validity of the results of each technique is checked by statistical methods like histogram analysis and cross validation approach. The proposed methodology is presented with an application to field information of a carbonate oil reservoir with a relatively high level of heterogeneity, located in the Persian Gulf, Iran. The results indicate that constructed 3D geological models provide realistic descriptions of reservoir permeability considering available geological interpretations of studied area.

Well-Integrity Evaluation for Methane-Hydrate Production in the Deepwater Nankai Trough

Summary Large accumulations of methane hydrates are known to exist in the deepwater Nankai Trough off the southern coast of Japan. Because of its enormous potential as an energy source, there is growing interest in the production of methane gas from these deposits. An offshore production test was scheduled to test the technological viability to produce the methane hydrate with a depressurization method. However, methane-hydrate production may cause large amounts of compaction and subsidence, which can damage well integrity and cause loss of zonal isolation in the overburden. This condition could provide potential leakage pathways for methane gas to the surface and endanger offshore operations. The paper presents a study in which well integrity was evaluated for a methane-hydrate-production test well in the Nankai Trough. In this study, a new work flow was proposed and applied to honor both fieldwide formation heterogeneity and near-wellbore geometry. The geomechanics properties were determined through integration of seismic inversion data, log data, and core data from the Nankai Trough. Interface elements were installed between the casing and cement and the cement and formation to evaluate the impact of cement-bond quality on the well integrity. The numerical simulation was conducted through coupling of the simulation results produced by a methane-hydrate production simulator from a third party with a 3D finite-element geomechanics simulator. The study predicted the occurrence of 2 cm of subsidence on the seafloor generated by approximately 1.5% of reservoir compaction for a production test of 20 days. Over this period, casing would yield with a plastic strain of approximately 1%. Most findings indicated a low risk in the loss of zonal isolation that is consistent with the results of the production test conducted in March 2013. This simulation evaluated potential risks related to well integrity, and provided critical information for the preparation and execution of the pioneering offshore methane-hydrate production test in the Nankai Trough.

CFD simulation on the generation of turbidites in deepwater areas: a case study of turbidity current processes in Qiongdongnan Basin, northern South China Sea

Turbidity currents represent a major agent for sediment transport in lakes, seas and oceans. In particular, they formulate the most significant clastic accumulations in the deep sea, which become many of the world’s most important hydrocarbon reservoirs. Several boreholes in the Qiongdongnan Basin, the northwestern South China Sea, have recently revealed turbidity current deposits as significant hydrocarbon reservoirs. However, there are some arguments for the potential provenances. To solve this problem, it is essential to delineate their sedimentary processes as well as to evaluate their qualities as reservoir. Numerical simulations have been developed rapidly over the last several years, offering insights into turbidity current behaviors, as geologically significant turbidity currents are difficult to directly investigate due to their large scale and often destructive nature. Combined with the interpretation of the turbidity system based on high-resolution 3D seismic data, the paleotophography is acquired via a back-stripping seismic profile integrated with a borehole, i.e., Well A, in the western Qiongdongnan Basin; then a numerical model is built on the basis of this back-stripped profile. After defining the various turbidity current initial boundary conditions, including grain size, velocity and sediment concentration, the structures and behaviors of turbidity currents are investigated via numerical simulation software ANSYS FLUENT. Finally, the simulated turbidity deposits are compared with the interpreted sedimentary bodies based on 3D seismic data and the potential provenances of the revealed turbidites by Well A are discussed in details. The simulation results indicate that a sedimentary body develops far away from its source with an average grain size of 0.1 mm, i.e., sand-size sediment. Taking into account the location and orientation of the simulated seismic line, the consistence between normal forward simulation results and the revealed cores in Well A indicates that the turbidites should have been transported from Vietnam instead of Hainan Island. This interpretation has also been verified by the planar maps of sedimentary systems based on integration of boreholes and seismic data. The identification of the turbidity provenance will benefit the evaluation of extensively distributed submarine fans for hydrocarbon exploration in the deepwater areas.

Climatic control of the late Quaternary turbidite sedimentology of Lake Kivu, East Africa: Implications for deep mixing and geologic hazards

The Lake Kivu catchment in the East African Rift is subject to various geologic hazards, including frequent volcanic eruptions, earthquakes, and potential limnic overturns and degassing events. Integration of high-resolution seismic reflection data, 14 C dated sediment cores, and lake-floor bathymetry reveals large axial and transverse turbidite systems in the eastern basin of the lake. The turbidites were sourced by hyperpycnal river flows during exceptional floods, and the temporal occurrence of the turbidites was climatically controlled. The turbidite record over the past ∼12 k.y. is correlated with the regional paleohydrologic records from tropical East Africa. Our study suggests that flood-introduced turbidites preserved in deep lakes are indicators of hydrological changes, and that extreme floods in Lake Kivu9s recent history may have triggered deep mixing events. This study also has implications for the current degassing efforts in Lake Kivu; potential geologic hazards may be triggered by extraordinary turbidity currents, and need to be considered in the design and deployment of gas extraction facilities.

EMSE: Synergizing EM and seismic data attributes for enhanced forecasts of reservoirs

New developments of electromagnetic and seismic techniques have recently revolutionized the oil and gas industry. Time-lapse seismic data is providing engineers with tools to more accurately track the dynamics of multi-phase reservoir fluid flows. With the challenges faced in distinguishing between hydrocarbons and water via seismic methods, the industry has been looking at electromagnetic techniques in order to exploit the strong contrast in conductivity between hydrocarbons and water. Incorporating this information into reservoir simulation is expected to considerably enhance the forecasting of the reservoir, hence optimizing production and reducing costs. Conventional approaches typically invert the seismic and electromagnetic data in order to transform them into production parameters, before incorporating them as constraints in the history matching process and reservoir simulations. This makes automatization difficult and computationally expensive due to the necessity of manual processing, besides the potential artifacts. Here we introduce a new approach to incorporate seismic and electromagnetic data attributes directly into the history matching process. To avoid solving inverse problems and exploit information in the dynamics of the flow, we exploit petrophysical transformations to simultaneously incorporate time lapse seismic and electromagnetic data attributes using different ensemble Kalman-based history matching techniques. Our simulation results show enhanced predictability of the critical reservoir parameters and reduce uncertainties in model simulations, outperforming with only production data or the inclusion of either seismic or electromagnetic data. A statistical test is performed to confirm the significance of the results. • Synergizing EM and seismic data improve reservoir forecasts. • Efficient integration of seismic and EM data attributes. • EnKF and iterative EnKF outperform EnRML. • Inclusion of seismic and EM reduces ensemble spreads of Ensemble Filter. • Better prediction of permeability and porosity spatial profiles.

Improved reservoir characterization and monitoring of the Long Lake heavy oil SAGD project using time-lapse multicomponent seismic data

Kelsey Schiltz, Loren Zeigler and David Gray demonstrate how the integration of timelapse compressional and multi-component seismic data has resulted in a geologic model of low permeability shales and enhanced the understanding of the steam chamber through imaging of the heat and pressure fronts in the Long Lake bitumen field in Alberta, Canada. Long Lake is a bitumen field covering 63,000 acres within the Athabasca oil sands in Alberta, Canada. Bitumen is a special type of heavy oil that is less than 10 API and is immobile at in situ conditions. Long Lake bitumen (~8 API) is produced from the Lower Cretaceous McMurray Formation using an in situ thermal recovery method called steam-assisted gravity drainage (SAGD).

Decrypting geophysical signals at Stromboli Volcano (Italy): Integration of seismic and Ground-Based InSAR displacement data.

We present the integration of seismic and Ground-Based Interferometric Synthetic Aperture Radar system (GBInSAR) displacement data at Stromboli Volcano. Ground deformation in the area of summit vents is positively correlated with both seismic tremor amplitude and cumulative amplitudes of very long period (VLP) signals associated with Strombolian explosions. Changes in VLP amplitudes precede by a few days the variations in ground deformation and seismic tremor. We propose a model where the arrival of fresh, gas-rich magma from depth enhances gas slug formation, promoting convection and gas transfer throughout the conduit system. At the shallowest portion of the conduit, an increase in volatile content causes a density decrease, expansion of the magmatic column and augmented degassing activity, which respectively induce inflation of the conduit, and increased tremor amplitudes. The temporal delay between increase of VLP and tremor amplitudes/conduit inflation can be interpreted in terms of the different timescales characterizing bulk gas transfer versus slug formation and ascent.

Improving the integration of gravity gradiometry and seismic data and where gravity data has the greatest impact

Abstract Neil Dyer1 and Claire Husband, present a new technique that enables gravity and seismic data to work better together.

Time-Lapse Seismic Data Integration Incorporates Pressure and Saturation Effects

This article, written by Special Publications Editor Adam Wilson, contains highlights of paper SPE 166395, ’Streamline-Based Time-Lapse Seismic-Data Integration Incorporating Pressure and Saturation Effects,’ by Shingo Watanabe, SPE, Jichao Han, SPE, Akhil Datta-Gupta, SPE, and Michael J. King, SPE, Texas A&M University, prepared for the 2013 SPE Annual Technical Conference and Exhibition, New Orleans, 30 September-2 October. The paper has not been peer reviewed. This paper presents an efficient history matching approach that simultaneously integrates 4D repeat seismic surveys with well production data. This approach is particularly well-suited for the calibration of the reservoir properties of high-resolution geologic models because the seismic data are areally dense but sparse in time, while the production data are continuous in time but averaged over interwell spacing. The joint history matching is performed using streamline-based sensitivities derived from either finite-difference or streamline-based flow simulation. Introduction Previous studies have made attempts at quantitative 4D seismic history matching. However, the reconciliation of reservoir model heterogeneity with temporal changes in seismic attributes remains a particularly complex task. Several dynamic data integration algorithms have been proposed in the literature, which can be categorized broadly into three data integration levels: (1) reservoir-simulation- based integration between the pressure and saturation estimates inverted from seismic observation data and the direct simulated saturation and pressure responses, (2) petroelastic-based integration between the seismic inverted rock elastic properties derived from a geophysical inversion and the simulated rock elastic responses from the simulated saturation and pressure responses by means of petroelastic models, and (3) seismic-forward-model-based integration between the direct seismic traces attributes and the simulated seismic responses by means of seismic wave propagation modeling. The seismic-forward-model-based seismic data integration approach uses direct seismic trace data and circumvents the uncertainties associated with the seismic-inversion process. The general workflow for generating synthetic seismic data from a reservoir simulation model generally involves (1) static reservoir properties on the simulation grid, (2) simulation of dynamic pressure and fluid saturations at each cell, (3) computation of seismic elastic properties, and (4) simulation of the seismic attribute by applying a seismic wave propagation model over the reservoir interval and the overburden rock. This study examines both reservoir-simulation- based calibration and rock-physics- based calibration. In the first instance, the authors calibrate against time-lapse changes in both pressure and saturation. In the second instance, they calibrate against the time-lapse change in acoustic impedance. In both cases, the inversion will provide local updates to the reservoir model using analytic streamline- based sensitivity calculations.

Origin and anatomy of two different types of mass–transport complexes: A 3D seismic case study from the northern South China Sea margin

Integration of 2D and 3D seismic data from the Qiongdongnan Basin along the northwestern South China Sea margin has enabled the seismic stratigraphy, seismic geomorphology and emplacement mechanisms of eight separate, previously undocumented, mass–transport complexes (MTCs) to be characterized. These eight MTCs can be grouped into two types:(1) Localized detached MTCs, which are confined to submarine canyons and cover hundreds of km2, consist of a few tens of km3 remobilized sediments and show long striations at their base. They resulted from small-scale mass-wasting processes induced by regional tectonic events and gravitational instabilities on canyon margins.(2) Regional attached MTCs, which occur within semi-confined or unconfined settings and are distributed roughly perpendicular to the strike of the regional slope. Attached MTCs occupy hundreds to thousands of km2 and are composed of tens to hundreds of km3 of remobilized sediments. They contain headwall escarpments, translated blocks, remnant blocks, pressure ridges, and basal striations and cat-claw grooves. They were created by large-scale mass-wasting processes triggered by high sedimentation rates, slope oversteepening by shelf-edge deltas, and seismicity.Our results show that MTCs may act as both lateral and top seals for underlying hydrocarbon reservoirs and could create MTC-related stratigraphic traps that represent potential drilling targets on continental margins, helping to identify MTC-related hydrocarbon traps.