scholarly journals Petrofacies and diagenetic processes of la Victoria formation (Early Miocene), Dina oil field, upper Magdalena valley basin, Colombia.

2020 ◽  
Vol 10 (1) ◽  
pp. 33-44
Author(s):  
Juan Jose Gomez Caro ◽  
Angelica María Carreño Parra ◽  
María del Rosario P´érez Trejos ◽  
Edgar Ricardo Pérez ◽  
Luis Fernando Peña Peña ◽  
...  
Keyword(s):  
Oil Field ◽  
Early Miocene ◽  
Hydrocarbon Migration ◽  
Clastic Rocks ◽  
Diagenetic Processes ◽  
Calcite Cement

The sandstones at the base of the Honda Group (La Victoria Formation - Early Miocene), in the Dina Field, Upper Magdalena Valley Basin (UMVB) – Colombia, which are present in the analyzed interval of the Dina Norte 27 and Dina Norte 37 wells, are composed of immature clastic rocks classified as Litharenites / Feldspathic Litharenites, due to the presence of volcanic fragments, feldspar / plagioclase and unstable minerals.They are texturally immature due to poor selection and low roundness of the detritus. The following sequence of diagenetic processes is proposed: minor compaction; grain coating by illite/smectite detritical clay, dissolution of unstable minerals, zeolite (heulandite) precipitation, partial precipitation of nonferroan calcite cement and finally chloritization of clays prior to hydrocarbon migration.

scholarly journals Diagenetic Processes Overprint and Pore Types of Mauddud Formation, Badra Oil Field, Central Iraq

2020 ◽  
pp. 1353-1361
Author(s):  
Mena Jamal Faisal ◽  
Thamer A. Mahdi
Keyword(s):  
Effective Porosity ◽  
Oil Field ◽  
Reservoir Properties ◽  
Thin Sections ◽  
Diagenetic Processes ◽  
Different Types ◽  
Interparticle Porosity ◽  
Calcite Cement ◽  
Primary Porosity ◽  
Pore Types

Diagenetic processes and types of pores that control the reservoir properties are studied for Mauddud Formation in selected wells of Badra oil field, central Iraq. The microscopic study of the thin sections shows the effects of micritization, cementation, neomorphism, dissolution, dolomitization, compaction, and fracturing on Mauddud Formation carbonate microfacies. The decrease of porosity is resulted from cementation, compaction, and neomorphism. Different types of calcite cement occlude pore spaces such as drusy cement, syntaxial rim cement, and granular (blocky) cement. The neomorphism of micritic matrix and skeletal grains reduces porosity as indicated by development of microspar or pseudospar. Evidence of decreasing porosity by compaction includes closer packing of grains, which reduces interparticle porosity. Dissolution process has prominent effect in creating and increasing the effective porosity in different depositional textures of Mauddud Formation. Reservoir properties are increased in grain-supported microfacies, which have vuggy porosity or primary porosity, whose pore size differs depending on the size of the grains. The reservoir properties in the mud-supported microfacies are reduced due to the low occurrence of pores and their lack of connectivity if they exist.

Visualizing Hydrocarbon Migration Pathways Associated with the Ringhorne Oil Field, Norway: An Integrated Approach

2021 ◽  
pp. 1-57
Author(s):  
David Connolly ◽  
Kristoffer Rimaila ◽  
Assia Lakhlifi ◽  
Gabor Kocsis ◽  
Ingrid Fæstø ◽  
...  
Keyword(s):  
Neural Network ◽  
Integrated Approach ◽  
Upper Jurassic ◽  
Oil Field ◽  
Hydrocarbon Migration ◽  
Gas Chimney ◽  
Hydrocarbon Charge ◽  
Geochemical Studies ◽  
Elastic Inversion ◽  
Migration Pathways

Norway’s Ringhorne Field is a faulted anticline which produces oil from Triassic (Statfjord) and Paleocene (Hermod) sands. It is located on the Utsira High. Geochemical studies of the produced oil indicate the oil is generated from mature Upper Jurassic marine shales in the adjacent Viking Graben. However, it has not been clear how oil migrated into the Triassic reservoirs and charged the overlying Paleocene reservoirs. Gas chimney detection using a proven neural network technique was used to detect the vertical hydrocarbon migration pathways on normally processed seismic data. The processing results were then validated using a set of criteria to determine if they represented true hydrocarbon migration rather than seismic artifacts. The chimney processing results using this traditional (shallow) neural network was compared with convolutional neural network (deep learning) results and geo-mechanical modeling on key lines. Key reservoirs were delineated using a stochastic (elastic) inversion approach. Reliable chimneys were then visualized in the vicinity of the producing reservoirs. The results showed pathways by which the Triassic fluvial sands received charge, and how these reservoirs had flank leakage to provide charge to shallower Paleocene reservoirs. This approach has now been used over hundreds of fields and dry holes in the Norwegian North Sea and worldwide as analogs to assess hydrocarbon charge and top seal risk predrill.

scholarly journals Coupled experimental/numerical workflow for assessing quantitative diagenesis and dynamic porosity/permeability evolution in calcite-cemented sandstone reservoir rocks

2018 ◽  
Vol 73 ◽  
pp. 36 ◽  
Author(s):  
Steven Claes ◽  
Fadi H. Nader ◽  
Souhail Youssef
Keyword(s):  
Permeability Evolution ◽  
Flow Properties ◽  
New Approach ◽  
Reservoir Rocks ◽  
Pore Blocking ◽  
Diagenetic Processes ◽  
Porosity And Permeability ◽  
Sandstone Reservoir ◽  
Calcite Cement ◽  
Host Rocks

Some of the world best hydrocarbon reservoirs (carbonates and siliciclastics) are also believed to be valuable for subsurface storage of CO2 and other fluids. Yet, these reservoirs are heterogeneous in terms of their mineralogy and flow properties, at varying spatial-temporal scales. Therefore, predicting the porosity and permeability (flow properties) evolution of carbonates and sandstones remains a tedious task. Diagenesis refers to the alteration of sedimentary rocks through geologic time, mainly due to rock-fluid interactions. It affects primarily the flow properties (porosity and permeability) of already heterogeneous reservoir rocks. In this project a new approach is proposed to calculate/quantify the influence of diagenetic phases (e.g. dissolution, cement plugging) on flow properties of typical sandstone reservoir rocks (Early Jurassic Luxembourg Formation). A series of laboratory experiments are performed in which diagenetic phases (e.g. pore blocking calcite cement in sandstone) are selectively leached from pre-studied samples, with the quantification of the petrophysical characteristics with and without cement to especially infer permeability evolution. Poorly and heavily calcite-cemented sandstone samples, as well as some intermediate cemented samples were used. The results show a distinctive dissolution pattern for different cementation grades and varying Representative Elementary Volumes (REVs). These conclusions have important consequences for upscaling diagenesis effects on reservoirs, and the interpretation of geochemical modelling results of diagenetic processes. The same approach can be applied on other type of cements and host-rocks, and could be improved by integrating other petrophysical analyses (e.g. petroacoustic, NMR).

scholarly journals Investigation of Petrographic and Diagenetic Properties of Asmari Reservoir Cap Rock, SW Iran

2021 ◽  
Vol 2 (3) ◽  
pp. 248-257
Author(s):  
Samira Abbasi ◽  
Saeid Pourmorad ◽  
Ashutosh Mohanty
Keyword(s):  
Full Text ◽  
Oil Field ◽  
Oil Fields ◽  
Accurate Assessment ◽  
Diagenetic Processes ◽  
Bituminous Shale ◽  
Sw Iran ◽  
Cap Rock

Many problems in the production and development of oil fields lie in the correct and accurate assessment of the reservoir cap rock. Ramshir oil field is located 130 km southeast of Ahvaz and is one of the most important oil fields in the southwest of the country. To evaluate the petrographic and diagenetic properties, 300 thin microscopic sections were studied. According to petrographic studies, it was found that the cap rock in Ramshir oil field is composed of more evaporative sediments (mainly anhydrite with some gypsum) with some non-evaporative sediments (marl, carbonate and bituminous shale). The most important diagenetic processes in the study area were considered to be dolomitization, cementation, compaction, anhydrite, recrystallization and substitution. Petrographic and diagenetic studies suggest a swamp-swamp environment for this environment. Lithological changes are a sign of hot, humid, hot and dry weather during sedimentation of the cap rock of this field. Doi: 10.28991/HEF-2021-02-03-06 Full Text: PDF

Magnetic enhancement caused by hydrocarbon migration in the Mawangmiao Oil Field, Jianghan Basin, China

2006 ◽  
Vol 53 (1-2) ◽  
pp. 25-33 ◽  
Author(s):  
Qingsheng Liu ◽  
Qingsong Liu ◽  
Lungsang Chan ◽  
Tao Yang ◽  
Xianghua Xia ◽  
...  
Keyword(s):  
Oil Field ◽  
Hydrocarbon Migration ◽  
Magnetic Enhancement ◽  
Jianghan Basin

Diagenesis-driven pore fluid discrimination

2019 ◽  
Vol 38 (5) ◽  
pp. 366-373 ◽  
Author(s):  
Jack Dvorkin
Keyword(s):  
Acoustic Impedance ◽  
Rock Physics ◽  
Pore Fluid ◽  
Oil Field ◽  
Poisson's Ratio ◽  
Rock Properties ◽  
Fluid Substitution ◽  
Diagenetic Processes ◽  
Medium Porosity ◽  
Fluid Detection

In order to determine a direct hydrocarbon indicator in an oil field formed by low- to medium-porosity fast sandstone, we examine wireline data from four wells. Fluid substitution indicates that the sensitivity of the acoustic impedance and Poisson's ratio to oil-to-brine changes is very small. It appears, however, that due to diagenetic processes, the porosity in the brine-filled strata is noticeably smaller than that in the oil-saturated intervals. This porosity difference makes the impedance in the presence of oil noticeably smaller than that where brine is present. The respective impedance cutoff can serve as a discriminator for fluid detection in the seismically derived acoustic impedance volumes. The lesson learned is that merely relying on a rock-physics tool, such as fluid substitution, may not necessarily provide a fluid-detection recipe. Instead, we need to examine a plethora of natural events that may affect rock properties and then translate these effects into seismically detectable variables.

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