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.

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.

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.

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.

The Physical Properties and their Prediction of Volcanic Reservoirs in Luxi Area of Junggar Basin, China

2012 ◽  
Vol 616-618 ◽  
pp. 228-233
Author(s):  
Zhong Chun Sun ◽  
Zhong Hong Chen ◽  
Yu Hua Kong ◽  
Wen Liu ◽  
Men Yun Yang
Keyword(s):  
Physical Properties ◽  
Volcanic Rocks ◽  
Junggar Basin ◽  
Electrical Parameters ◽  
Clastic Rocks ◽  
Close Relationship ◽  
Porosity And Permeability ◽  
Different Characteristics ◽  
Volcanic Reservoirs ◽  
The Relationship

The physical properties of reservoirs determine the ability on accumulating hydrocarbon. As one of the unconventional hydrocarbon reservoirs, the volcanics own the different characteristics from the clastic rocks on physical properties. The study on the relationship between physical and electrical properties of deep volcanic reservoirs was conducted, using the Luxi area of Junggar basin as an example. By our study, some conclusions have been made: The heterogeneity of physical properties is strong in volcanic rocks whose porosity and permeability vary in different lithology and lithofacies; different rocks in a same well have various values of porosity and permeability, and a certain type of volcanic rock has different values of porosity and permeability in diverse wells. According to measured data, the value of porosity an permeability in erupting and effusive facies area are high, while in volcanic channel and extrusive facies as well as volcanic sedimentation facies are low. Unlike the clastic rocks, in volcanic rocks there is little relationship between porosity and permeability and all of them do not have close relationship to the buried depth. Different electrical responses have different relationship with the porosity of one certain lithology, while one certain electrical property has different responses for the porosities of different lithologies; comparatively speaking, the porosities of tuffites, breccia correlate intensively with GR, SP and AC, so these electrical parameters can be utilized to predict the physical properties. This study illustrated that the relativities between porosity and GR, AC, and SP are Por=-0.6189×GR+52.691 (R2=0.9311), Por =-0.3771×AC + 34.5 (R2=0.8876) and Por = 2.1458×SP + 79.404 (R2=0.8236).

scholarly journals A New Method to Determine the Lower Limit of Reservoir Physical Properties—Corrected Minimum Flow Pore-throat Radius Method

2021 ◽  
Vol 290 ◽  
pp. 03004
Author(s):  
Jinyou Dai ◽  
Lixin Lin ◽  
Rui Wang
Keyword(s):  
Physical Properties ◽  
Lower Limit ◽  
Traditional Method ◽  
Oil And Gas ◽  
Correction Method ◽  
New Method ◽  
Pore Throat ◽  
Throat Radius ◽  
Minimum Flow ◽  
Gas Accumulation

The lower limit of reservoir physical properties is an important parameter for identifying reservoirs and determining effective thickness in reserves evaluation, and is also an important basis for selecting perforated test intervals in oilfield exploration and development. There are many methods to determine the lower limit of reservoir physical properties, and the minimum flow pore throat radius method is one of the commonly used methods. The method uses 0.1μm as the minimum flow pore-throat radius, and uses this to calibrate the lower limit of reservoir physical properties. However, according to the water film theory, the minimum radius of the reservoir's flowing pore throat is not a definite value, but varies with the displacement dynamics. Therefore, there is no exact basis for using 0.1μm as the minimum flow pore-throat radius, so it needs to be corrected. To this end, a new method for determining the lower limit of reservoir physical properties—the corrected minimum flow pore-throat radius method is proposed. The correction method comprehensively considers the factors of oil and gas accumulation dynamics, and determines the lower limit of reservoir physical properties by obtaining the minimum flow pore-throat radius value suitable for oil and gas accumulation dynamics. A case study of Chang 63 reservoir in A Oilfield shows that the minimum flow pore radius of oil and gas determined by the correction method is 0.08 μm, and the lower limit of reservoir physical properties (porosity 9.1%, permeability 0.117 × 10-3 μm2). The traditional method has a minimum flow pore-throat radius of 0.1 μm and a lower limit of reservoir physical properties (porosity of 9.8% and permeability of 0.133 × 10-3 μm2). Due to full consideration of the impact of oil and gas accumulation dynamics, the minimum flow pore-throat radius determined by the correction method is more reliable than the traditional method, and the lower limit of the reservoir physical property calibrated by it has practical significance.

scholarly journals Characteristics of microscopic pore-throat structure of tight oil reservoirs in Sichuan Basin measured by rate-controlled mercury injection

Open Physics ◽  
2018 ◽  
Vol 16 (1) ◽  
pp. 675-684 ◽  
Author(s):  
Xinli Zhao ◽  
Zhengming Yang ◽  
Wei Lin ◽  
Shengchun Xiong ◽  
Yunyun Wei
Keyword(s):  
Sichuan Basin ◽  
Pore Radius ◽  
Oil Reservoirs ◽  
Tight Oil ◽  
Pore Throat ◽  
Tight Sandstone ◽  
Throat Radius ◽  
Mercury Injection ◽  
Rate Controlled ◽  
Tight Oil Reservoirs

Abstract Based on the results of rate-controlled mercury-injection experiments, the microscopic pore-throat structure characteristics of tight sandstone in Sha-1 Section and tight limestone in Da’anzhai Section of Sichuan Basin were quantitatively characterized. The results show that the pore radius distribution characteristics of tight oil reservoirs are similar. The main distribution is between 100~190 μm, and the average pore radius is 160 μm. While the distribution of the throat radius of tight sandstone and limestone is quite different, the distribution of the throat of sandstone samples is relatively concentrated, and the distribution of the throat of limestone samples is relatively sparse. There is a good positive correlation between the average throat radius and permeability, but the correlation between fractal dimension and permeability is not obvious. This indicates that the permeability is mainly affected by the radius of the throat. The pore-throat ratio in tight oil reservoirs is relatively large, and the resistance to seepage is greater during development. Therefore, during the development of tight oil, measures should be taken to increase the radius of the throat, reduce the ratio of pore radius to pore-throat radius, and improve the seepage capacity of the reservoir, thereby improving the development of tight oil.

scholarly journals Pore structures and reservoir characteristics of volcanic rocks in the Carboniferous Batamayineishan Formation in Shuangjingzi area, eastern Junggar Basin

2021 ◽  
Vol 36 (5) ◽  
pp. 105-119
Author(s):  
Masab Ali ◽  
Bian Weihua ◽  
Yang Kaikai ◽  
Muhammad Sabeh Khan Panni
Keyword(s):  
Large Scale ◽  
Oil And Gas ◽  
Volcanic Rocks ◽  
Junggar Basin ◽  
Sedimentary Basins ◽  
High Porosity ◽  
Throat Radius ◽  
Average Pore ◽  
Reservoir Characteristics ◽  
Mercury Injection

Junggar Basin is one of the largest sedimentary basins in Northwest China. Carboniferous oil and gas fields have been found in different areas in the eastern part of the Junggar Basin on a large scale, indicating that the Carboniferous rocks of the Junggar Basin have a huge potential for oil and gas exploration. This study focuses on the Batamayineishan Formation in the eastern part of the Junggar Basin, which contains volcanic rocks and pyroclastic rocks, aiming to investigate the reservoir characteristics and to identify the formation mechanism of the rocks of this formation. The majority of the existent reservoir space in the volcanic rocks of the Batamayineishan Formation is dominated by secondary pores and fractures. Using the methods of petrography, pressure-controlled mercury injection (PMI), and electron probe microanalysis (EPMA), the reservoir characteristics and diagenetic history of the volcanic rocks of the Batamayineishan Formation in the Shuangjingzi area were studied. A theoretical framework is established to provide favorable guidance for exploring Carboniferous volcanic rocks in the Junggar Basin. The results of mercury injection indicate that the average pore throat radius and porosity of the volcanic rocks are 0.068 µm and 6.62%, respectively. Permeability remains stable and does not show a significant change with an increase in porosity. Despite the high porosity, the permeability is relatively low, reflecting isolated and non-connected primary pores. The average value of permeability is relatively low (0.424×10-3 µm2), which typically suggests narrow micro-throats. Primary gas pores fill and develop amygdales on a large scale. In addition, the dissolution pores developed by dissolution and alteration also compensated for the decrease in the original gas pore volume.

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.

SANICRO 41

Alloy Digest ◽  
1995 ◽  
Vol 44 (1) ◽  
Keyword(s):  
Corrosion Resistance ◽  
Physical Properties ◽  
Oil And Gas ◽  
High Strength ◽  
Heat Treating ◽  
Gas Production ◽  
Oil And Gas Production ◽  
Corrosion Resistant ◽  
Corrosion Resistant Alloy ◽  
Nickel Base

Abstract SANDVIK SANICRO 41 is a nickel-base corrosion resistant alloy with a composition balanced to resist both oxidizing and reducing environments. A high-strength version (110) is available for oil and gas production. This datasheet provides information on composition, physical properties, and tensile properties. It also includes information on corrosion resistance as well as forming, heat treating, and joining. Filing Code: Ni-475. Producer or source: Sandvik.

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