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New Advances and Existed Problems for the Forming Mechanism of the Microbial Dolomite
Hao Wang,
Enzhao Xiao,
Yiyao Li,
Khalid Latif,
Muhammad Riaz
Issue:
Volume 6, Issue 6, November 2018
Pages:
126-133
Received:
4 July 2018
Accepted:
22 August 2018
Published:
12 October 2018
DOI:
10.11648/j.ogce.20180606.11
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Abstract: In the recent years, the study on the formation mechanism of microbial dolomite broadens the concept of "dolomite problem" perspective in sedimentology. The microbial dolomite model discusses sulfate reduction reaction, methane production, organic molecular hydrolysis and many other related topics under the same heading, which help in explaining the microbial metabolic mechanism of precipitated dolomite. Recent research on the dissolved sulfide precipitation of dolomite combined with the reduction reaction mechanism of sulfate provides a new understanding in promoting the mechanism of dolomite precipitation reduction reaction. Studies of the modern sedimentary environments highlighting the precipitation of primary dolomite induced by microbial accretion also represent the progress towards defining microbial dolomite. The striking results achieved in fixing the “dolomite problem” pointed out that the study of microbial processes contributing towards environment of primary dolomite precipitation and its mechanism may provide more thoughtful explanations for the microbial dolomite in the stratigraphic record. This study highlights that despite of the advancement in dolomite studies, adoption of microbial dolomite model only to explain the complex phenomenon of dolomite in geological record is limited and still need further research.
Abstract: In the recent years, the study on the formation mechanism of microbial dolomite broadens the concept of "dolomite problem" perspective in sedimentology. The microbial dolomite model discusses sulfate reduction reaction, methane production, organic molecular hydrolysis and many other related topics under the same heading, which help in explaining th...
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Application of Low Pressure N2 Adsorption on Shale Nanoscale Pore Structure: Examples from the Permian Shanxi Formation of Transitional Facies Shale
Delu Xie,
Suping Yao,
Rongjie Hu,
Biao Liu
Issue:
Volume 6, Issue 6, November 2018
Pages:
134-141
Received:
15 August 2018
Accepted:
29 August 2018
Published:
12 October 2018
DOI:
10.11648/j.ogce.20180606.12
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Abstract: Shale gas resources in transitional facies are important unconventional energy sources. In order to understand the seepage characteristics of shale reservoir, low pressure nitrogen adsorption experiment were applied to investigate the nanoscale pore structure and adsorption fractal characteristics of shale in Shanxi Formation. FHH fractal model was adopted to calculate the absorption pore fractal dimension values D and quantitatively confirm the relationship between fractal dimension values and pore parameters. Results show that distribution curve obtained by the desorption branch present pore size distribution ranges from 1.14 nm to 173.39 nm, micropores and macropores developed and concentrated, no obvious dominant peak in the mesopores (2-25 nm) with relatively uniform distribution. Fractal dimension values range from 2.42 to 2.81, indicating shale pore structure is complex and heterogeneous. Fractal dimension is positively correlated with specific surface area and total pore volume, and highly negatively correlated with the average pore diameter. Fractal dimension is also a characterization of buried depth, and there is a weak positive correlation between them. With the increase of buried depth, fractal dimension has an increasing trend. The study provides a new method to further understand the shale nanometer pore structural heterogeneity.
Abstract: Shale gas resources in transitional facies are important unconventional energy sources. In order to understand the seepage characteristics of shale reservoir, low pressure nitrogen adsorption experiment were applied to investigate the nanoscale pore structure and adsorption fractal characteristics of shale in Shanxi Formation. FHH fractal model was...
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Research and Application of Commissioning Technology for LNG Tank Zero Discharge Commissioning
Kong Linghai,
Li Wenfeng,
Deng Wenyuan,
Tong Wenlong
Issue:
Volume 6, Issue 6, November 2018
Pages:
142-149
Received:
21 August 2018
Accepted:
4 September 2018
Published:
12 October 2018
DOI:
10.11648/j.ogce.20180606.13
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Abstract: Before cooling, the LNG tank is filled with nitrogen. During the test run, the tank will be gradually cooled from normal temperature to - 162 C. A large amount of BOG with high nitrogen content will be discharged to the torch in a short time, resulting in a great waste of resources. This paper discusses the difficulty of BOG recovery in LNG tank cooling by studying the conventional methods of LNG tank commissioning. Full nitrogen replacement and "BOG+LNG" tank cooling process are adopted before commissioning. The utilization efficiency of cold energy in receiving station is improved, the flow rate of BOG in receiving station is reduced, and the B in cooling process of LNG tank is realized. BOG zero emissions. The results showed that: (1) nitrogen in LNG tank could be fully replaced by "top intake and bottom exhaust" replacement method; (2) BOG + LNG cooling process could cool the tank, and effectively reduce the BOG flow rate in the cooling process of LNG tank to meet the processing capacity of receiving station and realize zero BOG emission in the cooling process of LNG tank. The technology of LNG tank zero emission commissioning has great reference value for the tank cooling of new storage tanks or receiving stations with the capacity of gasification and outward transportation. At the same time, "top intake bottom exhaust" nitrogen replacement, "BOG + LNG" cooling process has certain enlightenment for optimizing LNG tank design.
Abstract: Before cooling, the LNG tank is filled with nitrogen. During the test run, the tank will be gradually cooled from normal temperature to - 162 C. A large amount of BOG with high nitrogen content will be discharged to the torch in a short time, resulting in a great waste of resources. This paper discusses the difficulty of BOG recovery in LNG tank co...
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Analysis of Factors Affecting Residual Moveout Picking and Solutions
Issue:
Volume 6, Issue 6, November 2018
Pages:
150-158
Received:
10 September 2018
Accepted:
21 September 2018
Published:
23 October 2018
DOI:
10.11648/j.ogce.20180606.14
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Abstract: Reflection tomography on the base of common image gathers (CIGs) in offset domain or angle domain is the powerful and mostly used tool for velocity inversion. There are many factors that affect the accuracy and resolution of reflection tomography, in which RMO picking is a quite important one that can’t be ignored. Residual moveout Auto Picking on common image gathers is the most important step in tomography velocity inversion, the reliability of residual moveout picking decides the accuracy of tomography velocity inversion. Based on a case study of field data, the paper give a full discussions and experiences analysis of factors such as grid step, input data quality, geological structure, picking parameter, which affect residual moveout picking greatly. Furthermore, the paper also put forward corresponding suggestions and solutions to reduce or eliminate the impact of these factors on residual moveout picking. At last we implement a structure controlled residual moveout picking method with horizon constraint to a field data residual moveout picking. The proposed picking method refines the global picking though utilizing horizon constraint in vertical orientation and structure subdividing in lateral orientation. It effectively improves residual moveout quality and enhances inversion reliability, and also helps tomography inversion to update a velocity model with high resolution. The final prestack depth migration shows a good imaging of complex structures and faults, which demonstrates how important of the role that the fine residual moveout picking method plays in tomography inversion.
Abstract: Reflection tomography on the base of common image gathers (CIGs) in offset domain or angle domain is the powerful and mostly used tool for velocity inversion. There are many factors that affect the accuracy and resolution of reflection tomography, in which RMO picking is a quite important one that can’t be ignored. Residual moveout Auto Picking on ...
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Research & Prospect on Technical Essentials and Benefits of Input-Output of Alkali Surfactant Polymer
Zhang Qingsheng,
Yang Haiyan,
Zhou Xiya,
Sun Xiaobao,
Xiao Zuowei,
Li Yuqi,
Zhou Xianjun,
Liu Qingmei
Issue:
Volume 6, Issue 6, November 2018
Pages:
159-163
Received:
12 August 2018
Accepted:
8 October 2018
Published:
7 November 2018
DOI:
10.11648/j.ogce.20180606.15
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Abstract: In its 60 years’ development, Daqing oilfield has come to the later developing phrase of high water cut after going through the primary flowing production and secondary water flooding production, and faces a quite severe quandary. As the most important tertiary oil recovery technologies to increase crude oil production, the Alkali Surfactant Polymer flooding technique is becoming increasingly developed every day, it is a necessity for enhancing the output and producing benefit of Daqing oil field to correctly understand the economic principle of Alkali Surfactant Polymer flooding and to establish a scientific economic evaluation method and a reliable parameter system. Also, to carry out the study of economic evaluating based on investment, cost and revenue data of Alkali Surfactant Polymer flooding technique project which are implemented in recent years is of great importance in the industrial application of Alkali Surfactant Polymer flooding technique. It is of great importance to explore the effective method for economic evaluation of Alkali Surfactant Polymer flooding. Based on the completed projects, this paper summarizes the economic principle of input and output of those projects, attempts to effectively evaluate the economic situation of Alkali Surfactant Polymer flooding technique, and prospects of the economic benefit of the industrial application of Alkali Surfactant Polymer flooding technique primarily.
Abstract: In its 60 years’ development, Daqing oilfield has come to the later developing phrase of high water cut after going through the primary flowing production and secondary water flooding production, and faces a quite severe quandary. As the most important tertiary oil recovery technologies to increase crude oil production, the Alkali Surfactant Polyme...
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Qualitative Discuss on Well Test Curve Uncertainty Analysis in Remaining oil Evaluation of Thick Bottom Reservoir
Ren Chaoqun,
Li Wenhong,
Xue Guoqing,
Chen Xin,
Lin Ruimin,
Zhang Peng,
Wang Mingwei
Issue:
Volume 6, Issue 6, November 2018
Pages:
164-170
Received:
31 July 2018
Accepted:
18 October 2018
Published:
9 November 2018
DOI:
10.11648/j.ogce.20180606.16
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Abstract: In directional wells of thick bottom water reservoir, partial perforation is usually applied to prevent rapid coning of bottom water. Because of the existence of interlayers, water driving conditions and remaining oil distribution become complex. In partially perforated wells in the survey area oil saturation of lower unperforated section can’t be tested directly due to the influence of completion structure. The "spherical flow" characteristics cannot be seen from the pressure derivative curve during the pressure building. The uncertainty analysis of well-test curve is used in the analysis of interpretation model, Kz/Kr value and boundary feature. The results show that the unperforated section at the lower part, slightly affected by the water flooding, contributes less to oil production. Through the study on reservoir numerical simulation mechanism, it’s concluded that in oil wells driven by bottom, water cut features rapid rise in early stage and slow rise in later stage. The water cut rise curve mainly belongs to a convex type. In contrast, in oil well driven by edge water, water cut rises slowly in early stage but rapidly later. The water cut curve is mainly a concave type. The research well shows a concave type in the water cut curve. Test data shows the well is driven by edge water under the influence of interlayer. The unperforated section at the lower part of reservoir where the remaining oil concentrates can become the target of further tapping.
Abstract: In directional wells of thick bottom water reservoir, partial perforation is usually applied to prevent rapid coning of bottom water. Because of the existence of interlayers, water driving conditions and remaining oil distribution become complex. In partially perforated wells in the survey area oil saturation of lower unperforated section can’t be ...
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An Equation for the Adsorption Under Variable Temperature and Pressure Condition
Li Dong,
Hao Jingyuan,
Ma Qinghua,
Zhang Xuemei
Issue:
Volume 6, Issue 6, November 2018
Pages:
171-176
Received:
9 October 2018
Accepted:
21 November 2018
Published:
19 December 2018
DOI:
10.11648/j.ogce.20180606.17
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Abstract: A temperature-pressure-adsorption equation (TPAE) has been introduced to treat accurately the adsorption under variable temperature and pressure of 4 coal seams with different ranks. The TPAE has four parameters, two parameters (A, B) relate the testing coal properties, one parameter ∆ relates temperature influence, one parameter β relate to pressure influence. All necessary pieces information, such as adsorption, partial differential of temperature, partial differential of pressure, and complete differential, can be accurately calculated. When temperature effect ∆ and pressure effect β of coal sample has been measured and under certain temperature and pressure conditions, maximum adsorption occurs and inter-related to coal metamorphism (Vitrines maximum reflectivity). The accuracy of TPAE, regarding the fitting of the adsorption under variable temperature and pressure of 4 coal seams with different ranks, has been verified either with the average relative error or with pictorial illustration. Since TPAE is an equation with triple variable (temperature, pressure, adsorption volume), its partial and full derivations, are conducted to interpret numerically why and how the temperature increasing has negative effect, but pressure increasing has positive effect. Furthermore, partial derivations of TPAE have shown that the temperature effect and pressure effect are intertwine. Finally, the “variable temperature and pressure adsorption” method has been suggested to replace the conventional series isothermal adsorption for the evaluation of adsorptive power of coal under a certain geological condition of temperature and pressure.
Abstract: A temperature-pressure-adsorption equation (TPAE) has been introduced to treat accurately the adsorption under variable temperature and pressure of 4 coal seams with different ranks. The TPAE has four parameters, two parameters (A, B) relate the testing coal properties, one parameter ∆ relates temperature influence, one parameter β relate to pressu...
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The Mathematical Analysis of Temperature-Pressure-Adsorption Data of Deep Shale Gas
Hao Jingyuan,
Li Dong,
Zhang Xuemei,
Ma Qinghua
Issue:
Volume 6, Issue 6, November 2018
Pages:
177-182
Received:
9 October 2018
Accepted:
14 November 2018
Published:
19 December 2018
DOI:
10.11648/j.ogce.20180606.18
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Abstract: Coal is a porous medium and natural adsorbent with well-developed void system. Coal bed gas is usually defined as a hydrocarbon gas, which is adsorbed mainly on the surface of coal matrix particles, free in coal pores or dissolved in coal seam water. The adsorption amount of solid to gas is a function of temperature and gas pressure. Adsorption of gas content in shale is not only an important parameter for shale gas geological reserves and recoverable reserves, but also a key indicator for designing the production process. As the buried depth increases, the temperature and pressure of the reservoir also increase. Therefore, it is necessary to establish an equation to organically link the independent variables and dependent variables such as temperature, pressure, shale, methane adsorption amount to predict adsorptive gas content in shale. Temperature-pressure-adsorption equation (TPAE) has been used to treat the series isothermal adsorption data of 4 kinds of shale rock published by Li Wuguang. In the test temperature and pressure range, TPAE can not only simplify Langmuir parameters, but also picture the quantitative relationship around the temperature-pressure-adsorption. If known TPAE parameters, and the changing temperature and pressure, the partial differential of temperature results in the negative effects of temperature. Furthermore, both the partial differential of pressure and total differential can be exactly calculated. This method using temperature pressure adsorption equation provides a new idea for predicting the adsorption capacity of shale gas. It can make more accurate calculation for shale gas content under variable temperature and pressure.
Abstract: Coal is a porous medium and natural adsorbent with well-developed void system. Coal bed gas is usually defined as a hydrocarbon gas, which is adsorbed mainly on the surface of coal matrix particles, free in coal pores or dissolved in coal seam water. The adsorption amount of solid to gas is a function of temperature and gas pressure. Adsorption of ...
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Development and Application of High Thermostable Elasto-Toughness Latex Cement Slurry System for Ultra-deep Gas Wells
Guangguo Yang,
Peiqing Lu,
Xiaoyu Du,
Yuan Gao,
Laiyu Sang
Issue:
Volume 6, Issue 6, November 2018
Pages:
183-189
Received:
1 November 2018
Accepted:
30 November 2018
Published:
19 December 2018
DOI:
10.11648/j.ogce.20180606.19
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Abstract: To solve the challenges in the cementing of ultra-deep high-temperature and high-pressure (HTHP) gas wells, a latex cement slurry system with good high thermostable anti-gas channeling and elasto-toughness performances was developed, which uses the styrene-butadiene latex DC200 to enhance the anti-channeling performance of cement slurry and reduce the permeability of set cement, and additionally use modified elastic particles, organic polymer fibers and inorganic mineral fibers as composite toughening materials to enhance the elasto-toughness of set cement effectively. The evaluation results show that the temperature resistance of this system is above 160°C, the SPN value is <1, and the static gelling strength transition time is only 12 min, indicating a good anti-channeling performance. Compared with the conventional set cement, the permeability was reduced by about 80%, the elastic modulus was reduced by about 60%, the bending strength was increased by about 84%, and the impact resistance of set cement was increased by about 86.69%, showing excellent mechanical properties. This system has been successively applied in well SHN-401 and well SHN-4-1 in Tazhong Oilfield, and the overall cementing quality was good. It proves that this cement slurry system can meet the cementing technical requirements for ultra-deep HTHP gas wells, and has good application prospect.
Abstract: To solve the challenges in the cementing of ultra-deep high-temperature and high-pressure (HTHP) gas wells, a latex cement slurry system with good high thermostable anti-gas channeling and elasto-toughness performances was developed, which uses the styrene-butadiene latex DC200 to enhance the anti-channeling performance of cement slurry and reduce ...
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The Research of Bohai Sea-Based Annulus Protection Fluid
Ren Yi,
Lu Yuan,
Zhang Mao,
Cheng Yan,
Sun Jixing,
Wang Zhongguang
Issue:
Volume 6, Issue 6, November 2018
Pages:
190-195
Received:
8 November 2018
Accepted:
4 December 2018
Published:
26 December 2018
DOI:
10.11648/j.ogce.20180606.20
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Abstract: The advantages and disadvantages of oil-based and freshwater-based annulus protection fluids were compared. According to the characteristics of freshwater shortage on offshore platforms, the quality of Bohai sea water was analyzed in detail. The sterilization effect of various fungicides was evaluated by extinction dilution method in the laboratory, and the quaternary ammonium salt YHZWJ-15 was determined as one of the basic components. After that, the method of industry evaluation standard was used to conclude that polyphosphate BH-701 has excellent scale prevention performance. For the most important corrosion inhibitor in the system, BHH-509, which is composed of gluconate, organic amine, zinc salt and organic phosphonic acid copolymer, is successfully compounded by static corrosion rate method. Finally, the polarization curve was used to analyze the action mechanism of the annulus protection fluid, and the basic ratio was seawater + 0.5% YHZWJ-15 + 0.01% BHF-701A + 0.01% thiourea + 0.5% BHH-509. It can reduce the corrosion rate to 0.0051 mm/a and the corrosion inhibition rate can reach more than 95%.
Abstract: The advantages and disadvantages of oil-based and freshwater-based annulus protection fluids were compared. According to the characteristics of freshwater shortage on offshore platforms, the quality of Bohai sea water was analyzed in detail. The sterilization effect of various fungicides was evaluated by extinction dilution method in the laboratory...
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The Study of Sedimentary Facies in Daqing Oilfield from the Perspective of Science of Science
Issue:
Volume 6, Issue 6, November 2018
Pages:
196-200
Received:
8 November 2018
Accepted:
13 December 2018
Published:
14 January 2019
DOI:
10.11648/j.ogce.20180606.21
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Abstract: The sedimentary facies research in Daqing oilfield has gone through a process of generating ideas, conducting research, and achieving results, the achievements of which have been widely applied in oilfield production1. The research is a very typical case in the history of petroleum science and technology with strong science of science significance, which is in conformity with the universal law of science of science on the emergence, development and maturity of new science and technology. It came into being along with the actual needs of the development and production of Daqing oilfield，and was gradually formed and has been gradually improved through step by step exploration and accumulation under the guidance of scientific methodology. The principle of science of science points out that there are three necessary conditions for the existence and development of a new theoretical doctrine, the case of Daqing oilfield fully complied with the principle: it not only contains the scope of the original theory, but also can solve the problems that the original theory are unable to solve, and may further predict the future development, so it has a strong vitality. Meanwhile，science of science also points out that it is almost impossible for a new science and technology to emerge smoothly without obstacles and setbacks. This study is just such a case, which was initially accused of heresy, not accepted by some authorities. However, after being tested through repeated practice, it has finally established its status, and has still been playing an important role in the development process of Daqing Oilfield.
Abstract: The sedimentary facies research in Daqing oilfield has gone through a process of generating ideas, conducting research, and achieving results, the achievements of which have been widely applied in oilfield production1. The research is a very typical case in the history of petroleum science and technology with strong science of science significance,...
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Experimental and Theoretical Characterization of Sand-Carrying by Heavy Oil-Flow in a Horizontal Wellbore
Hong Gao,
Zhiming Wang,
Xiaoqiu Wang,
Dongying Wang
Issue:
Volume 6, Issue 6, November 2018
Pages:
201-213
Received:
13 November 2018
Accepted:
4 December 2018
Published:
18 January 2019
DOI:
10.11648/j.ogce.20180606.22
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Abstract: The world's heavy oil reserves are very large. With the wide application of heavy oil cold recovery technology, the problem of blockage in oil well caused by the deposition of sand in the wellbore is becoming more and more serious. Therefore, it is very important to study the deposition and migration of sand in the wellbore. Based on indoor full-sized experimental apparatus simulating multiphase complex flows, the sand-carrying capacity of heavy oil in pipes is determined using a high-viscosity white oil and water mixture as the fluid medium, and by varying parameters such as the saturation, sand volume concentration, viscosity of heavy oil, and flow. A complete investigation is performed to obtain the basis of the sand flow in pipes and sand-bed development and migration. It is shown that the viscosity of heavy oil, main flow rate, and water content have a significant effect on the sand-carrying capacity of heavy oil, while the effect of the wall inflow on the pressure drop of the wellbore is relatively less. Based on the examination of the experimental flow pattern, an oil–water–sand-bed three-layer pressure drop model with a variable-mass flow is established for the first time. The minimum energy method is used to calculate the model. The model considers the diffusion of solid-phase particles and pressure drop by the fluid of the sand bed in heavy oil and is verified against the pressure drop data obtained from the experiments. The results show that the model is within an average relative error of 12.69%, which is satisfactory for practical engineering. Furthermore, the model provides a theoretical support for reasonable sand production in heavy oil reservoirs.
Abstract: The world's heavy oil reserves are very large. With the wide application of heavy oil cold recovery technology, the problem of blockage in oil well caused by the deposition of sand in the wellbore is becoming more and more serious. Therefore, it is very important to study the deposition and migration of sand in the wellbore. Based on indoor full-si...
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