scholarly journals Gravity anomalies, sub-surface structure and oil and gas migration in the Mamfe, Cameroon-Nigeria, sedimentary basin

2007 ◽  
Vol 46 (2) ◽  
pp. 129-139
Author(s):  
Théophile Ndougsa-Mbarga ◽  
Eliezer Manguelle-Dicoum ◽  
José-Oscar Campos-Enriquez
Keyword(s):  
Surface Structure ◽  
Oil And Gas ◽  
Sedimentary Basin ◽  
Gravity Anomalies ◽  
Gas Migration

Este estudio reporta resultados preliminares de una interpretación formal de datos existentes de un área hasta hoy desprovista de estudios geofísicos, la cuenca de Mamfe (Camerún nor-occidental/ Nigeria sur-oriental). La importancia de esta cuenca se comprende por el hecho de que está genéticamente relacionada con la depresión de Benue productora de hidrocarburos. Los mapas de anomalías gravimétricas regional y residual proporcionaron información sobre la estructura de la cuenca. Las componentes gravimétricas regional y residual se obtuvieron ajustando con el método de mínimos cuadrados una superfi cie polinomial de tercer grado a la anomalía de Bouguer. La anomalía residual de tercer orden revela la presencia de dos bajos gravimétricos orientados NE-SW. La anomalía occidental cubre las poblaciones de Ekok y Agbokem, y la oriental comprende a Mukonyong, Mamfe y Bachuo Akagbe. Dos cinturones orientados aproximadamente E-W de anomalías gravimétricas positivas limitan por el norte y el sur respectivamente a las anomalías antes descritas. En general los bajos gravimétricos son debidos al relleno sedimentario de la cuenca, en tanto que las anomalías residuales positivas son el producto de afloramientos del complejo basamental. El patrón de las anomalías nos permite inferir las características generales de la cuenca. Ella comprende dos sub-cuencas separadas por un alto estructural. La cuenca occidental es la más profunda y compuesta. Comprende dos sub-cuencas separadas por un alto estructural menor, posiblemente relacionado con la continuación hacia la cuenca del complejo cristalino. En general, estas sub-cuencas tienden a ser más someras hacia el oriente indicando que la cuenca evolucionó de oeste a este. Las direcciones de migración de hidrocarburos probablemente generados en el depocentro han sido indicadas. La acumulación de hidrocarburos a lo largo de estas direcciones es posible, pero estudios sísmicos y gravimétricos más detallados deben ser emprendidos para buscar trampas estructurales o estratigráficas. Este estudio puede servir de base a un programa integral de exploración petrolera.

Analysis of Fault Characteristics and Reservoir Forming Control in Middle Fault Depression Belt in Hailer-Tamtsag Basin

2012 ◽  
Vol 616-618 ◽  
pp. 174-184
Author(s):  
Yong He Sun ◽  
Lin Kang ◽  
Feng Xiang Yang ◽  
Xue Song Li
Keyword(s):  
Oil And Gas ◽  
Source Rocks ◽  
Fault System ◽  
Type I ◽  
Weathering Crust ◽  
Gas Migration ◽  
Block Boundary ◽  
System Type ◽  
Fracture Damage ◽  
Buried Hill

In order to reveal in middle fault depression belt of Hailer-Tamtsag Basin buried hill oil and gas migration and accumulation characteristics, we summarize controlling effect of fault on oil and gas migration and accumulation of buried hill, which by analysing genetic mechanism of buried hills based on fault systems formation and evolution. Research shows that three types of fault system in Hailer-Tamtsag Basin: early stretched fault system(Type I), early stretched middle tensile shearing fault system(Type I-II), early stretched middle tensile shearing reverse late fault system(Type I-II-III). Type I-II and I-II-III are stretching by NW tensional stress in Nantun group ,which afford tectonic framework for syngenesis buried hill and epigenetic buried hill. Type I make buried hills complicated .It is also favorable to ancient geomorphological buried hill in the fault less affected zones. Although they formed cracks dense zone easier, Type I-II and I-II-III fault system damage the reservoir which is not conducive to " hydrocarbon-supplying window " formation; Type I fault system have less promotion on the development of the buried hill reservoir, while it is conducive to hydrocarbon accumulation as the block boundary in buried hill hydrocarbon. Fault formed source rocks two kinds for hydrocarbon mode: unidirectional and bidirectional, which formed two reservoir-forming pattern: Unidirectional transportation hydrocarbon of weathering crust or hydrocarbon of fracture damage zones and bidirectional transportation hydrocarbon of weathering crust or hydrocarbon of fracture damage zones.

Controlling Factors of Hydrocarbon Accumulation in Talaha-Changjiaweizi Area

2013 ◽  
Vol 734-737 ◽  
pp. 1175-1178
Author(s):  
Hong Qi Yuan ◽  
Ying Hua Yu ◽  
Fang Liu
Keyword(s):  
Physical Properties ◽  
Oil And Gas ◽  
Controlling Factors ◽  
Source Rocks ◽  
Hydrocarbon Accumulation ◽  
Gas Migration ◽  
Main Controlling Factors ◽  
Sedimentary Microfacies ◽  
Plane Distribution ◽  
Distributary Channel

Based on the analysis of the relationships between the conditions of structures, sedimentations, source rocks, cap rocks, faults, oil and gas migration passages and traps and hydrocarbon accumulation, the controlling factors of hydrocarbon accumulation and distribution was studied in Talaha-changjiaweizi area. It is held that the source rocks control the hydrocarbon vertical distribution, the drainage capabilities control the hydrocarbon plane distribution, fracture belts control the hydrocarbon accumulation of Talaha syncline, underwater distributary channel is a favorable accumulation environment and reservoir physical properties control the oil and water distributions. Therefore, it is concluded that source rocks, fracture belts, sedimentary microfacies and reservoir physical properties are the main controlling factors of hydrocarbon accumulation and distribution in Talaha-changjiaweizi area.

Predicting gas migration through existing oil and gas wells

2018 ◽  
Vol 25 (4) ◽  
pp. 121-132 ◽  
Author(s):  
James A. Montague ◽  
George F. Pinder ◽  
Theresa L. Watson
Keyword(s):  
Oil And Gas ◽  
Gas Migration ◽  
Gas Wells ◽  
Oil And Gas Wells

scholarly journals Basin Depth Mapping Beneath Wellington City Based on Residual Gravity Anomalies

2021 ◽  
Author(s):  
◽  
Alistair Stronach
Keyword(s):  
Gravity Anomaly ◽  
Sedimentary Basin ◽  
Gravity Data ◽  
Three Dimensional ◽  
Maximum Amplitude ◽  
Central Business District ◽  
Gravity Anomalies ◽  
Depth Map ◽  
Capital City ◽  
Detailed Knowledge

<p><b>New Zealand’s capital city of Wellington lies in an area of high seismic risk, which is further increased by the sedimentary basin beneath the Central Business District (CBD). Ground motion data and damage patterns from the 2013 Cook Strait and 2016 Kaikōura earthquakes indicate that two- and three-dimensional amplification effects due to the Wellington sedimentary basin may be significant. These effects are not currently accounted for in the New Zealand Building Code. In order for this to be done, three-dimensional simulations of earthquake shaking need to be undertaken, which requires detailed knowledge of basin geometry. This is currently lacking, primarily because of a dearth of deep boreholes in the CBD area, particularly in Thorndon and Pipitea where sediment depths are estimated to be greatest.</b></p> <p>A new basin depth map for the Wellington CBD has been created by conducting a gravity survey using a modern Scintrex CG-6 gravity meter. Across the study area, 519 new high precision gravity measurements were made and a residual anomaly map created, showing a maximum amplitude anomaly of -6.2 mGal with uncertainties better than ±0.1 mGal. Thirteen two-dimensional geological profiles were modelled to fit the anomalies, then combined with existing borehole constraints to construct the basin depth map. </p> <p>Results indicate on average greater depths than in existing models, particularly in Pipitea where depths are interpreted to be as great as 450 m, a difference of 250 m. Within 1 km of shore depths are interpreted to increase further, to 600 m. The recently discovered basin bounding Aotea Fault is resolved in the gravity data, where the basement is offset by up to 13 m, gravity anomaly gradients up to 8 mGal/km are observed, and possible multiple fault strands identified. A secondary strand of the Wellington Fault is also identified in the north of Pipitea, where gravity anomaly gradients up to 18 mGal/km are observed.</p>

scholarly journals SEPARATE QUANTITATIVE PREDICTION OF OIL AND GAS CONTENT PROSPECTS FOR DZHEBOL STAGE PALEOZOIC DEPOSITS OF TIMAN-PECHORA OIL AND GAS BASIN

2015 ◽  
pp. 9-15
Author(s):  
A. I. Diyakonov ◽  
L. V. Parmuzina ◽  
S. V. Kochetov ◽  
A. Yu. Malikova
Keyword(s):  
Oil And Gas ◽  
Sedimentary Basin ◽  
Scientific Basis ◽  
Source Rocks ◽  
Gas Content ◽  
Quantitative Prediction ◽  
Oil And Gas Resources ◽  
Gas Bearing

It is shown that the evolutionary-catagenetic model for calculating the initial potential hydrocarbon resources can serve as a scientific basis for the separate quantitative prediction of areas of oil-and-gas content. In this case retrospectively evaluated are the scales of generation and accumulation of hydrocarbons in the source rocks during catagenetic evolution of sedimentary basin. The authors propose a method, the results of evaluation of generation and accumulation scales and initial potential oil and gas resources for major oil-and-gas bearing complexes of Dzhebol stage.

Gas migration from oil and gas fields and associated hazards

1993 ◽  
Vol 9 (3) ◽  
pp. 223-238 ◽  
Author(s):  
A.E. Gurevich ◽  
B.L. Endres ◽  
J.O. Robertson ◽  
G.V. Chilingar
Keyword(s):  
Oil And Gas ◽  
Gas Migration ◽  
Oil And Gas Fields ◽  
Gas Fields

GEOLOGICAL STRUCTURE OF THE SURFACE OF THE PALEOZOIC FOLDED BASE OF THE WEST OF THE TURAN PLATFORM

2021 ◽  
Vol 82 (3) ◽  
pp. 19-26
Author(s):  
POPKOV VASILY I. ◽  
Keyword(s):  
Surface Structure ◽  
Oil And Gas ◽  
Geological Structure ◽  
Comprehensive Analysis ◽  
Tectonic Structures ◽  
The West ◽  
Seismic Surveys ◽  
Gravity And Magnetic ◽  
Morphostructural Zoning ◽  
Gas Potential

The surface of the folded base of the platforms is an important geological boundary separating rock complexes formed in different geodynamic settings and characterized by different physical properties, which largely determine the patterns of formation of minerals in them. Therefore, determining the depth of its occurrence and morphology is not only theoretical, but also practical. Despite many years of studying the foundation of the west of the Turan Platform, there is no unity among geologists and geophysicists in their ideas about its structure, depth of occurrence and surface structure. In this regard, the aim of the work is to build a structural map of the surface of the foundation of the west of the Turan plate, to identify the main tectonic structures and their morphology. The construction is based on a comprehensive analysis of drilling materials and geophysical data. When drawing up the structural map, all the currently available geological and geophysical material was used, including data from drilling, gravity and magnetic surveys, and seismic surveys of various modifications, which made it possible to perform fairly detailed and reliable constructions. The article provides a detailed description of the surface structure of the folded base of the west Turan platform. The obtained results can be used in solving the issues of oil and gas potential of the studied territory. The folded base of the western Turan plate is a heterogeneous and heterochronous formation, differentiated by the depth of occurrence, which allows for morphostructural zoning of its surface.

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