scholarly journals Role Played by Oil Emplacement in Controlling Pore Network Evolution of Tight Sandstones

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Huifang Hu ◽  
Yang Ju ◽  
Chenyang Zhao ◽  
Miaozhi Jing ◽  
Liang Sun ◽  
...  

Whether oil emplacement and diagenetic sequences provoke, deteriorate, or have no effect on pore network evolution, as implied by recent tests and theoretical analysis, are critical factors in forecasting hydrocarbon exploration and development potentials. Therefore, a systematic investigation on the effect of oil emplacement of tight sandstones is conducted to study the importance of this behavior on the pore evolution path. This study evaluated the role played by oil emplacement and diagenesis in the pore network evolution of Upper Triassic tight sandstones in the Ordos Basin. To help provide a comprehensive understanding, we have used a multidisciplinary method including physical properties, casting thin section, scanning electron microscope, X-ray diffraction, fluorometric, and inclusion analysis. The results demonstrate that the sandstones could be divided into four groups based on new criteria: calcareous sandstone, high soft component sandstone, low soft component sandstone with continual oil emplacement, and low soft component sandstone with intermittent oil emplacement. The physical properties of those types of sandstones were gradually reduced. Quartz cement captured hydrocarbon, carbonate captured hydrocarbon, free hydrocarbon, and adsorbed hydrocarbon were the four main kinds of hydrocarbons. The maturity of those sandstones was decreased progressively, indicating that the formation time of those hydrocarbons was favorable to maturity. Four stages of oil emplacement happened, and large-scale emplacement mainly occurred in the late Jurassic and early Craterous. The evidence demonstrated that tight sandstones’ high porosity could be attributed to positive diagenetic contributions with a complex interplay of chemical compaction, early formed clays, and large-scale oil emplacement. This work would provide new sights for a better understanding of the tight oil accumulation modes, and the findings could be applied in the hydrocarbon exploration and development field.

2021 ◽  
pp. 014459872110493
Author(s):  
Baobao Wang ◽  
Xiucheng Tan ◽  
Wenjie Su ◽  
Wei Yan ◽  
Di Xiao ◽  
...  

In gypsum–carbonate rock assemblages, multistage and complex fluids control the formation of dolomite reservoirs that are a focus of hydrocarbon exploration. It is difficult to determine the types of dolomite reservoirs and their formation mechanisms due to the diverse rock assemblages and multiple stages of diagenesis. In this study, we investigated the petrology, reservoir physical properties, and geochemistry of the 6th sub-member of member five of the Majiagou Formation (i.e. Ma56) in the Ordos Basin, China. These data were used to determine the nature and types of gypsum–carbonate rocks, and constrain their reservoir characteristics and diagenetic history, and fluid-related mechanisms that led to dolomite reservoir development and preservation. The Ma56 was deposited on a restricted evaporatic platform in the North China Craton, and contains three main types of dolomite reservoirs with variable types of reservoir space. Dolomite reservoir formation was closely related to penecontemporaneous dolomitization, karstification, and differential cementation. Early large-scale dolomitization produced dolomitized carbonate sediments that were resistant to compaction and dissolution, which was conducive to the preservation of primary and secondary pores. The intermittent exposure and dissolution of mound–shoal facies sediments, due to high-frequency sea-level fluctuations, was the dominant mechanism for formation of secondary dissolved pores and high-quality reservoirs. During burial, differential cementation occurred due to interaction between fluids and pore size, which determined the extent of reservoir preservation. In general, the studied dolomite reservoirs have undergone multistage diagenesis and alteration, which led to complex and multistage development of the reservoir porosity. However, the reservoir lithology and pore space developed mostly in the depositional to penecontemporaneous stages. Our results provide new insights into the origins of deeply buried dolomite reservoirs in carbonate–evaporite successions.


1978 ◽  
Vol 18 (1) ◽  
pp. 204
Author(s):  
D. McMinn

Rapidly rising costs have created operating and investment problems for companies involved in the Australian hydrocarbon resource industry. Expenditure in this area has declined markedly in constant dollar terms, an adverse trend given Australia's outlook for increasing reliance on imported crude oil in the 1980's.Costs in hydrocarbon exploration appear to have risen in excess of general inflation in the Australian economy. This situation may be attributed to the strong upward movement in wages and equipment costs, and in some cases, the low level of domestic exploration in the mid-1970's.Capital costs for hydrocarbon development and pipeline projects in Australia have also escalated, a trend caused by rising wage levels in project construction and increases in equipment costs. Additional factors such as design alterations, environmental considerations and labour disputes, can also add significantly to costs. Large scale hydrocarbon projects, which have long lead times, are susceptible to inflationary trends.Increasing amounts of funds are required for exploration and development as a result of the rising cost trend. However, difficulty is being experienced in raising funds through capital and equity markets, as well as retained earnings. A key factor in securing adequate funds is profitability, which is largely determined by the State and Federal Governments. For the smaller oil and gas producers, the past profitability record has been inadequate, although the improvement in recent years should continue because of higher oil and gas prices.Costs may be expected to continue to increase in hydrocarbon exploration and development, but probably at a lower rate than experienced in the mid- 1970's. The future viability of the hydrocarbon sector is dependent on a favourable investment environment and higher profitability to offset the considerable risks in exploration and escalation in costs.


Energies ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 470
Author(s):  
Yue Zhang ◽  
Jingchun Tian ◽  
Xiang Zhang ◽  
Jian Li ◽  
Qingshao Liang ◽  
...  

Diagenesis and pore evolution of tight sandstone reservoir is one of the most important issues surrounding clastic reservoirs. The tight sandstone of the Shanxi Formation is an important oil and gas producing layer of the Upper Paleozoic in Ordos Basin, and its densification process has an important impact on reservoir quality. This study determined the physical properties and diagenetic evolution of Shanxi Formation sandstones and quantitatively calculated the pore loss in the diagenetic process. Microscopic identification, cathodoluminescence, and a scanning electron microscope were used identify diagenesis, and the diagenesis evolution process was clarified along with inclusion analysis. In addition, reservoir quality was determined based on the identification of pore types and physical porosity. Results show that rock types are mainly sublitharenite and litharenite. The reservoir has numerous secondary pores after experiencing compaction, cementation, and dissolution. We obtained insight into the relationship between homogenous temperature and two hydrocarbon charges. The results indicated that there were two hydrocarbon charges in the Late Triassic–Early Jurassic (70–90 °C) and Middle Jurassic–Early Cretaceous (110–130 °C) before reservoir densification. The quantitative calculation of pore loss shows that the average apparent compaction, cementation, and dissolution rates are 67.36%, 22.24%, and 80.76%, respectively. Compaction directly affected the reservoir tightness, and intense dissolution was beneficial to improve the physical properties of the reservoir.


2019 ◽  
Vol 7 (3) ◽  
pp. T687-T699
Author(s):  
Shuwei Ma ◽  
Dazhong Ren ◽  
Lifa Zhou ◽  
Fengjuan Dong ◽  
Shi Shi ◽  
...  

Diagenesis is one of the most important factors impacting the performance of many reservoirs and is perhaps the most important factor impacting the performance of tight sandstone reservoirs, such as those of the Sulige gas field in the Ordos Basin of China. However, the relationship between diagenesis and related parameters determining reservoir physical properties remains unclear. Therefore, we have analyzed experimental data from high-pressure mercury intrusion porosimetry, scanning electron microscopy, and thin sections in addition to using a porosity recovery calculation model to investigate microscopic characteristics, diagenesis, and pore-evolution processes of the low-permeability tight gas reservoir of the He-8 unit of the Sulige gas field in the Ordos Basin. In addition, we have identified the impacts of diagenesis on reservoir characteristics and established the relationship between diagenesis and reservoir quality evolution. We also used the Beard primary porosity model to recover the primary porosity, and to built the reducing and enhancing calculation models for intergranular pore, dissolution pore, and intercrystalline pore during diagenesis. Based on the quantitative relationship between diagenesis processes and porosity evolution, we found that the results of simulation calculation and experimental works were in close agreement with minimal error.


Crystals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 885
Author(s):  
Nicole Knoblauch ◽  
Peter Mechnich

Zirconium-Yttrium-co-doped ceria (Ce0.85Zr0.13Y0.02O1.99) compacts consisting of fibers with diameters in the range of 8–10 µm have been successfully prepared by direct infiltration of commercial YSZ fibers with a cerium oxide matrix and subsequent sintering. The resulting chemically homogeneous fiber-compacts are sinter-resistant up to 1923 K and retain a high porosity of around 58 vol% and a permeability of 1.6–3.3 × 10−10 m² at a pressure gradient of 100–500 kPa. The fiber-compacts show a high potential for the application in thermochemical redox cycling due its fast redox kinetics. The first evaluation of redox kinetics shows that the relaxation time of oxidation is five times faster than that of dense samples of the same composition. The improved gas exchange due to the high porosity also allows higher reduction rates, which enable higher hydrogen yields in thermochemical water-splitting redox cycles. The presented cost-effective fiber-compact preparation method is considered very promising for manufacturing large-scale functional components for solar-thermal high-temperature reactors.


Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 864
Author(s):  
Suguna Perumal ◽  
Raji Atchudan ◽  
Thomas Nesakumar Jebakumar Immanuel Edison ◽  
Rajendran Suresh Babu ◽  
Petchimuthu Karpagavinayagam ◽  
...  

The growth of industry fulfills our necessity and promotes economic development. However, pollutants from such industries pollute water bodies which pose a high risk for living organisms. Thus, researchers have been urged to develop an efficient method to remove toxic heavy metal ions from water bodies. The adsorption method shows promising results for the removal of heavy metal ions and is easy to operate on a large scale, thus can be applied to practical applications. Numerous adsorbents were developed and reported, among them hydrogels, which attract great attention because of the reusability, ease of preparation, and handling. Hydrogels are generally prepared by the cross-linking of polymers that result in a three-dimensional structure, showing high porosity and high functionality. They are hydrophilic in nature because of the functional groups, and are non-toxic. Thus, this review provides various methods of hydrogel adsorbents preparation and summarizes recent progress in the use of hydrogel adsorbents for the removal of heavy metal ions. Further, the mechanism involved in the removal of heavy metal ions is briefly discussed. The most recent studies about the adsorption method for the treatment of heavy metal ions contaminated water are presented.


Minerals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 453
Author(s):  
Wenhuan Li ◽  
Tailiang Fan ◽  
Zhiqian Gao ◽  
Zhixiong Wu ◽  
Ya’nan Li ◽  
...  

The Lower Jurassic reservoir in the Niudong area of the northern margin of Qaidam Basin is a typical low permeability sandstone reservoir and an important target for oil and gas exploration in the northern margin of the Qaidam Basin. In this paper, casting thin section analysis, scanning electron microscopy, X-ray diffraction, and stable isotope analysis among other methods were used to identify the diagenetic characteristics and evolution as well as the main factors influencing reservoir quality in the study area. The predominant types of sandstone in the study area are mainly feldspathic lithic sandstone and lithic arkose, followed by feldspathic sandstone and lithic sandstone. Reservoir porosity ranges from 0.01% to 19.5% (average of 9.9%), and permeability ranges from 0.01 to 32.4 mD (average of 3.8 mD). The reservoir exhibits robust heterogeneity and its quality is mainly influenced by diagenesis. The Lower Jurassic reservoir in the study area has undergone complex diagenesis and reached the middle diagenesis stage (A–B). The quantitative analysis of pore evolution showed that the porosity loss rate caused by compaction and cementation was 69.0% and 25.7% on average, and the porosity increase via dissolution was 4.8% on average. Compaction was the main cause of the reduction in the physical property of the reservoir in the study area, while cementation and dissolution were the main causes of reservoir heterogeneity. Cementation can reduce reservoir space by filling primary intergranular pores and secondary dissolved pores via cementation such as a calcite and illite/smectite mixed layer, whereas high cement content increased the compaction resistance of particles to preserve certain primary pores. δ13C and δ18O isotopes showed that the carbonate cement in the study area was the product of hydrocarbon generation by organic matter. The study area has conditions that are conductive to strong dissolution and mainly occur in feldspar dissolution, which produces a large number of secondary pores. It is important to improve the physical properties of the reservoir. Structurally, the Niudong area is a large nose uplift structure with developed fractures, which can be used as an effective oil and gas reservoir space and migration channel. In addition, the existence of fractures provides favorable conditions for the uninterrupted entry of acid fluid into the reservoir, promoting the occurrence of dissolution, and ultimately improves the physical properties of reservoirs, which is mainly manifested in improving the reservoir permeability.


2019 ◽  
Vol 219 (3) ◽  
pp. 1698-1716 ◽  
Author(s):  
M Malovichko ◽  
A V Tarasov ◽  
N Yavich ◽  
M S Zhdanov

SUMMARY This paper presents a feasibility study of using the controlled-source frequency-domain electromagnetic (CSEM) method in mineral exploration. The method has been widely applied for offshore hydrocarbon exploration; however, nowadays this method is rarely used on land. In order to conduct this study, we have developed a fully parallelized forward modelling finite-difference (FD) code based on the iterative solver with contraction-operator preconditioner. The regularized inversion algorithm uses the Gauss–Newton method to minimize the Tikhonov parametric functional with the Laplacian-type stabilizer. A 3-D parallel inversion code, based on the iterative finite-difference solver with the contraction-operator preconditioner, has been evaluated for the solution of the large-scale inverse problems. Using the computer simulation for a synthetic model of Sukhoi Log gold deposit, we have compared the CSEM method with the conventional direct current sounding and the CSEM survey with a single remote transmitter. Our results suggest that, a properly designed electromagnetic survey together with modern 3-D inversion could provide detailed information about the geoelectrical structure of the mineral deposit.


2008 ◽  
Vol 27 (1) ◽  
pp. 51-57 ◽  
Author(s):  
W Nicholson Price II ◽  
Yang Chen ◽  
Samuel K Handelman ◽  
Helen Neely ◽  
Philip Manor ◽  
...  

Author(s):  
Ilmira R. Gilmutdinova ◽  
Elena Kostromina ◽  
Regina D. Yakupova ◽  
Petr S. Eremin

The development of new biomaterials whose characteristics are as close as possible to the properties of living human tissues is one of the most promising areas of regenerative medicine. This work aimed at creating a bioplastic material based on collagen, elastin and hyaluronic acid and studying its structure and properties to assess the prospects for further use in clinical practice. Bioplastic material was obtained by mixing collagen, hyaluronic acid and elastin in predetermined proportions with distilled water. We treated the material with photochemical crosslinking to stabilize biofilm in a liquid medium and form a nanostructured scaffold. A commercial human skin fibroblast cell culture was used to assess the biomaterial cytotoxicity and biocompatibility. The visualization and studies of the biomaterial structure were performed using light and scanning electron microscopy. It has been shown that the obtained biomaterial is characterized by high resilience; it has also a high porosity. The co-culturing of the bioplastic material and human fibroblasts did not reveal any of its cytotoxic effects on cells in culture. It was shown that the biomaterial samples could maintain physical properties in the culture medium for more than 10 days, while the destruction of the matrix was observed 3–4 weeks after the beginning of incubation. Thus, the created biomaterial can be used on damaged skin areas due to its physical properties and structure. The use of the developed biomaterial provides effective conditions for good cell proliferation, which allows us to consider it as a promising wound cover for use in clinical practice.


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