Thin section and X-ray computed tomography for characterizing volcanic reservoirs in Chagan Sag, Yin-E Basin, China

2020 ◽  
Vol 8 (4) ◽  
pp. T777-T791
Author(s):  
Xiaoming Sun ◽  
Siyuan Cao ◽  
Zicheng Niu
Keyword(s):  
Computed Tomography ◽  
Oil And Gas ◽  
Volcanic Rocks ◽  
Oil Accumulation ◽  
Thin Sections ◽  
Tomographic Images ◽  
Factors Affecting ◽  
Computed Tomography Images ◽  
Organic Fluids ◽  
Volcanic Reservoirs

We have synthesized macroscopic data (cores) and microscopic data (thin sections and computed tomography images) to characterize volcanic oil and gas reservoir spaces in the Chagan Sag, Yin-E Basin, China. We also have assessed the controlling factors affecting the formation of these reservoirs. Primary pores significantly improve the reservoir quality because they enable the formation of secondary pores (dissolution pores) by allowing migration, alteration, and filling by inorganic and organic fluids. Consequently, the development of secondary pores modifies the permeability of the volcanic rocks. The formation of volcanic reservoirs is influenced by lithology, diagenic minerals, faults, and fractures. The size and abundance of pores, especially gas pores, varies with the lithology. Gas pores are consistently larger and more abundant in basalts than in andesites and tuffs. Moreover, the carbonates and chlorites readily dissolve in the vesicles and fractures, thus resulting in the formation of secondary pores. However, quartzes are not susceptible to dissolution in this study area. Further, faults and fractures are necessary for the formation of reservoir spaces and for oil and gas migration. The tomographic images provide 3D distributions of fractures, vesicles, and matrix dissolution pores. The results suggest that fractures connecting isolated gas pores provide favorable spaces for oil accumulation.

scholarly journals Weakly supervised semantic segmentation of tomographic images in the diagnosis of stroke

2021 ◽  
Vol 2099 (1) ◽  
pp. 012021
Author(s):  
A V Dobshik ◽  
A A Tulupov ◽  
V B Berikov
Keyword(s):  
Computed Tomography ◽  
Network Architecture ◽  
Semantic Segmentation ◽  
Training Data ◽  
Neural Network Architecture ◽  
Brain Images ◽  
Tomographic Images ◽  
Computed Tomography Images ◽  
Segmentation Accuracy ◽  
Weakly Supervised

Abstract This paper presents an automatic algorithm for the segmentation of areas affected by an acute stroke in the non-contrast computed tomography brain images. The proposed algorithm is designed for learning in a weakly supervised scenario when some images are labeled accurately, and some images are labeled inaccurately. Wrong labels appear as a result of inaccuracy made by a radiologist in the process of manual annotation of computed tomography images. We propose methods for solving the segmentation problem in the case of inaccurately labeled training data. We use the U-Net neural network architecture with several modifications. Experiments on real computed tomography scans show that the proposed methods increase the segmentation accuracy.

Characteristics and prediction of weathered volcanic rock reservoirs: A case study of Carboniferous rocks in Zhongguai paleouplift of Junggar Basin, China

2018 ◽  
Vol 6 (2) ◽  
pp. T431-T447 ◽  
Author(s):  
Xiaoming Sun ◽  
Siyuan Cao ◽  
Xiao Pan ◽  
Xiangyang Hou ◽  
Hui Gao ◽  
...  
Keyword(s):  
Oil And Gas ◽  
Volcanic Rocks ◽  
Geophysical Methods ◽  
Junggar Basin ◽  
Hydrocarbon Exploration ◽  
Background Information ◽  
Long Time ◽  
Volcanic Reservoirs ◽  
Fluid Detection

Volcanic reservoirs have been overlooked for hydrocarbon exploration for a long time. Carboniferous volcanic rocks of the Zhongguai paleouplift contain proven reserves of [Formula: see text]. We have investigated the volcanic reservoirs integrating cores, well, and seismic data, and the proposed volcanic reservoir distribution is controlled by the weathering function, fractures, and lithology. The weathering process makes the originally tight igneous rocks become good-quality reservoirs, and fractures play an important role in connecting different types of pores and act as reservoir space. Isolated and ineffective pores become effective ones due to connection among fractures. Only volcanic breccia can be good-quality reservoirs without any weathering function. The nonlinear chaos inversion controlled by weathered layers shows that the good-quality reservoirs are distributed in the top of the weathering crust and the structural high. Furthermore, fluid-detection attributes and background information prove that oil and gas are distributed along the paleostructural high. The objectives of this study were to (1) describe the characteristics of volcanic reservoirs and determine the controlled rules for reservoir distribution, (2) characterize the distribution of reservoirs and hydrocarbon, and (3) propose an effective workflow for hydrocarbon exploration in volcanic rocks combining geologic and geophysical methods.

scholarly journals A Comparative Study on Microscopic Characteristics of Volcanic Reservoirs in the Carboniferous Kalagang and Haerjiawu Formations in the Santanghu Basin, China

2021 ◽  
Vol 9 ◽  
Author(s):  
Weiming Wang ◽  
Weihao La ◽  
Tanguang Fan ◽  
Xiongfei Xu ◽  
Yingnan Liu ◽  
...  
Keyword(s):  
Physical Properties ◽  
Oil And Gas ◽  
Volcanic Rocks ◽  
High Yield ◽  
Tight Oil ◽  
Pore Throat ◽  
Pore Structures ◽  
Mercury Injection ◽  
Oil Flow ◽  
Volcanic Reservoirs

Self-jetting high-yield oil flow was obtained from Ma 67 and Ma 36 wells drilled in the volcanic reservoirs of the Haerjiawu Formation in the Santanghu Basin, China. This has shifted the prospectors’ attention to the Haerjiawu Formation from the Kalagang Formation, which is generally considered to have favorable physical properties. To further explain the geological reasons why oil flow can jet itself from the volcanic rocks in the Haerjiawu Formation with poor physical properties, this study carries out a systematic comparison on the microscopic pore structures of volcanic rocks through unconventional tests such as low-temperature nitrogen adsorption, high-pressure mercury injection, and constant-rate mercury injection based on the analyses of physical properties and minerals. The results obtained are as follows. The volcanic rocks of the Kalagang Formation have relatively high pore permeability. However, their micropores have a wide distribution range of pore size and feature highly meandering structures and strong heterogeneity. Meanwhile, small pore throats connect large pores in the volcanic rocks, resulting in a relatively high pore/throat ratio. All these are conducive to the occurrence of tight oil and gas but unfavorable for the flow of oil and gas. The volcanic rocks in the Haerjiawu Formation have relatively low volcanic permeability. However, small pores connect large pore throats in the volcanic rocks; thus, leading to a relatively low pore/throat ratio. Meanwhile, the volcanic rocks feature low meandering structures, strong homogeneity, and high connectivity. All these are favorable for the formation of tight oil and gas reservoirs. These assessment results also indicate that the assessment indices of tight volcanic reservoirs should not only include porosity and permeability. Instead, more attention should be paid to the microscopic pore structures, and it is necessary to analyze the charging and flow of tight oil from the configuration of pores and pore throats. This study not only explains the geological factors of the wells with self-jetting high-yield oil flow in the Haerjiawu Formation from the perspective of microscopic pore structures but also provides a new idea and comparison method for the assessment of tight reservoirs in other areas.

Factors Affecting Prostate Volume Estimation in Computed Tomography Images

2011 ◽  
Vol 36 (1) ◽  
pp. 85-90 ◽  
Author(s):  
Cheng-Hsiu Yang ◽  
Shyh-Jen Wang ◽  
Alex Tong-Long Lin ◽  
Chao-An Lin
Keyword(s):  
Computed Tomography ◽  
Prostate Volume ◽  
Volume Estimation ◽  
Factors Affecting ◽  
Computed Tomography Images

scholarly journals MIP and CT Scanning Characterization of Pore Structure of Tight Volcanic Rocks

2021 ◽  
Author(s):  
Yunliang Yu ◽  
Haibo Xu ◽  
Ye Bai ◽  
Huijing Zhang ◽  
Wenqing Niu ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Pore Structure ◽  
Oil And Gas ◽  
Volcanic Rocks ◽  
Three Dimensional ◽  
Ct Scanning ◽  
Micro Ct ◽  
Gas Reservoirs ◽  
Rock Samples ◽  
Unconventional Oil And Gas

Volcanic rocks are unconventional oil and gas reservoirs, and the pore structure of the rock is relatively complex. In this study, we selected samples from CS105 well and DS9 well from Yingcheng Formation volcanic reservoirs in the southern Songliao Basin to study the pore structure. First, we performed experiments on two rock samples using computed tomography (CT), and then measured the porosity and density of the two rock samples using mercury intrusion porosimetry (MIP). According to the data obtained by micron computed tomography (Micro-CT), Avizo 2019.1 software was used to perform three-dimensional (3D) reconstruction on the micron level of the two wellhead samples. Analyze the microscopic pore structure of the rock sample and compare it with the porosity of the sample obtained by the mercury injection method. Compared with MIP, Micro-CT more accurately characterizes the pore structure and porosity of volcanic rocks.

Hydrocarbon storage space within lacustrine gas shale of the Triassic Yanchang Formation, Ordos Basin, China

2015 ◽  
Vol 3 (2) ◽  
pp. SJ15-SJ23 ◽  
Author(s):  
Xiangzeng Wang ◽  
Lixia Zhang ◽  
Chengfu Jiang ◽  
Bojiang Fan
Keyword(s):  
Organic Matter ◽  
Oil And Gas ◽  
Ordos Basin ◽  
Storage Space ◽  
Oil Accumulation ◽  
Abrupt Decrease ◽  
Thin Sections ◽  
Yanchang Formation ◽  
Oil Generation ◽  
Gas Supply

The Triassic Yanchang Formation lacustrine shale is a source of conventional oil accumulation in the Ordos Basin, China. The Yanchang Formation, a hybrid system of organic-rich shale, interbedded silty shale, and siltstone, is believed to be a potential unconventional oil and gas play. Our crossdisciplinary investigation of the storage space included the outcrop description, core observation, thin sections, and scanning electron microscope pore imaging. We evaluated the results from these techniques to reveal that the storage space within the Yanchang Formation shales included primary intergranular pores, secondary generated pores, tectonic fractures, and bedding-parallel fractures. We conducted adsorption experiments, combined with burial and thermal history, in which the primary migration process can be divided into three stages. In the Early Jurassic, organic matter did not reach the oil generation threshold. From the Late Jurassic to the Early Cretaceous, organic matter entered the oil generation window, and gas was generated and stored as adsorbed gas, dissolved gas, and free gas. From the Middle to Late Cretaceous, the storage of shale gas was dynamically transformed by tectonic uplift. Variations in chemical and carbon isotopic compositions from canister-core desorption were directly related to the gas supply in shales. An abrupt decrease in gas dryness and positive [Formula: see text] values indicated the depletion of gas supply drainage. Our ultimate recovery factor reached 70%.

scholarly journals Reservoir Formation Model and Main Controlling Factors of the Carboniferous Volcanic Reservoir in the Hong-Che Fault Zone, Junggar Basin

Energies ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 6114
Author(s):  
Danping Zhu ◽  
Xuewei Liu ◽  
Shaobin Guo
Keyword(s):  
Physical Properties ◽  
Fault Zone ◽  
Oil And Gas ◽  
Hanging Wall ◽  
Volcanic Rocks ◽  
Soil Layer ◽  
Junggar Basin ◽  
Weathering Crust ◽  
Volcanic Reservoir ◽  
Volcanic Reservoirs

The Hong-Che Fault Zone is one of the important oil and gas enrichment zones in the Junggar Basin, especially in the Carboniferous. In recent five years, it has been proven that the Carboniferous volcanic rock has 140 million tons of oil reserves, and has built the Carboniferous volcanic reservoir with a capacity of million tons. Practice has proven that the volcanic rocks in this area have great potential for oil and gas exploration and development. To date, Carboniferous volcanic reservoirs have been discovered in well areas such as Che 32, Che 47, Che 91, Chefeng 3, Che 210, and Che 471. The study of drilling, logging, and seismic data shows that the Carboniferous volcanic reservoirs in the Hong-Che Fault Zone are mainly distributed in the hanging wall of the fault zone, and oil and gas have mainly accumulated in the high part of the structure. The reservoirs are controlled by faults and lithofacies in the plane and are vertically distributed within 400 m from the top of the Carboniferous. The Carboniferous of the Hong-Che Fault Zone has experienced weathering leaching and has developed a weathering crust. The vertical zonation characteristics of the weathering crust at the top of the Carboniferous in the area of the Che 210 well are obvious. The soil layer, leached zone, disintegration zone, and parent rock developed from top to bottom. Among these reservoirs, the reservoirs with the best physical properties are mainly developed in the leached zone. Based on a comprehensive analysis of the Carboniferous oil and gas reservoirs in areas of the Chefeng 3 and Che 210 wells, it is believed that the formation of volcanic reservoirs in the Hong-Che Fault Zone was mainly controlled by structures and was also controlled by lithofacies, unconformity surfaces, and physical properties.

scholarly journals Volcanic reservoirs: historic and current context

2021 ◽  
Vol 48 (1) ◽  
pp. e104451
Author(s):  
Patricia Lopes DESCOVI ◽  
Marcus Vinícius Berao ADE ◽  
Gabriela De Oliveira AVELLAR ◽  
Silvia Lorena Bejarano BERMÚDEZ ◽  
Fábio Pinto VIEIRA
Keyword(s):  
Oil And Gas ◽  
Volcanic Rocks ◽  
Historical Review ◽  
Oil And Gas Industry ◽  
Igneous Rocks ◽  
Daily Production ◽  
Gas Industry ◽  
Wide Range ◽  
The World ◽  
Volcanic Reservoirs

Within the oil and gas industry, igneous rocks are still seen as exploration and production challenges, due to their diverse petrogenesis and the wide range of values of some important petrophysical properties. This petrophysical variability depends on both primary and secondary processes. These facts made these rocks unattractive for decades. This condition is still observed in many fields around the world. This article has as main objective to make a historical review of studies developed globally with a focus on igneous rocks that act as a reservoir in petroleum systems. The review covered in this article was developed from a compilation of global data, thus allowing an overview of the countries that produce hydrocarbons in volcanic rocks, what types of rocks, geological age, and size of the reserve. Countries such as China and Indonesia stand out with higher daily production, exceeding orders of quantities of 108 cubic meters of gas and 104 tons of barrels of oil. In these countries, geological patterns are already being noticed in volcanic reservoirs, such as more recent geological ages and typical lithologies. Also, this work seeks to emphasize the importance of studying this type of reservoir, as its knowledge can lead to the solution of real problems within the world oil and gas industry.

Sign in / Sign up

Export Citation Format

Share Document