scholarly journals Unconsolidated fault vertical sealing ability evaluation method and its application during Stationary phase

2019 ◽  
Vol 23 (1) ◽  
pp. 35-42
Author(s):  
Ning Sun ◽  
Guang Fu ◽  
Lili Liu ◽  
Jingfeng Wu
Keyword(s):  
Stationary Phase ◽  
Evaluation Method ◽  
Oil And Gas ◽  
Relative Size ◽  
Reservoir Rock ◽  
Bohai Bay ◽  
Filling Material ◽  
Fault Rock ◽  
Sealing Ability ◽  
Oil Gas

To study the vertical distribution of oil, gas in the fracture zone of the oil and gas bearing basin, based on the mechanism and influence factors of vertical sealing oil and gas, this paper has studied the necessary conditions of unconsolidated fault vertical sealing oil, gas, determination method for compaction and diagenetic of the fault filling. Concluded that the static period of fault vertical sealing oil and gas required that fault should be cut by mudstone, through comparing the relative period of the fault rock starting consolidate and the fault stopping activity to determine whether the fracture fillings are compacted into rock. If the time fault rocks began compaction into rock is earlier than the time fault stopped activity, fault filling has been consolidated; otherwise not compaction. By determining the displacement pressure of the fracture filling material and the rock displacement pressure of the underlying reservoir, a method is established to evaluate static unconsolidated fault vertical sealing oil and gas ability by comparing the relative size of the two. Applied it in the evaluation of the vertical sealing capacity f1 in the one to three sections of the Dongying formation and 5 sections of the formation in the southern Bohai Bay Basin. The results show that the fault f1 in one to three of the Dongying formation have the greater filler displacement pressure than the displacement pressure of underlying reservoir rock, as the vertical sealed is favorable for oil and gas accumulation and preservation. It’s accordant with oil and gas distribution has been found in Dongying formation at present in the formation of the South Fort 5 structure, which indicates that the method is feasible to evaluate the vertical sealing ability of the fault in the stationary phase.

Research on HSE Risk Assessment and Control in Oil-Gas Drilling Operations

2014 ◽  
Vol 919-921 ◽  
pp. 500-506
Author(s):  
Fei Li ◽  
Guang Zhang
Keyword(s):  
Risk Assessment ◽  
Evaluation Method ◽  
Oil And Gas ◽  
Assessment System ◽  
Control Measures ◽  
Fuzzy Evaluation ◽  
Oil And Gas Exploration ◽  
Gas Drilling ◽  
Drilling Operations ◽  
Oil Gas

As the leading of oil and gas exploration and development, oil-gas drilling operations with high investment, high technology, and other industries interchange and perennial wild characteristics, there are various HSE risks during operation. Constructing HSE risk assessment system of oil-gas drilling operations, using AHP to construct indicators were analyzed and compared, and calculate the index weight. Then build fuzzy evaluation matrix based on expert evaluation method, get fuzzy evaluation result is "high risk". Finally, from four aspects (people, object, environment, and management) proposed HSE control measures.

scholarly journals Nanoindentation-Based Three-Parameter Fracability Evaluation Method for Continental Shales

2021 ◽  
Vol 9 ◽  
Author(s):  
Siwei Meng ◽  
Dongxu Li ◽  
Qi Wang ◽  
Jiaping Tao ◽  
Jian Su ◽  
...  
Keyword(s):  
Evaluation Method ◽  
Oil And Gas ◽  
Ordos Basin ◽  
Junggar Basin ◽  
Point Of View ◽  
Bohai Bay ◽  
Parameter Evaluation ◽  
Oil And Gas Resources ◽  
The Ordos Basin ◽  
Good Agreement

Shale fracturing evaluation is of great significance to the development of shale oil and gas resources, but the commonly used shale evaluation methods (e.g., the method using the brittleness index based on mineral composition or elastic parameters) have certain limitations. Fractures and beddings affecting fracturing are not considered in these methods. Therefore, it is necessary to develop a new method to evaluate fracturing more comprehensively. The samples used in this research were taken from four typical continental shale basins of China, namely the Bohai Bay Basin, the Ordos Basin, the Songliao Basin, and the Junggar Basin. From a microscopic point of view, a three-parameter evaluation method involving multi-dimensional factors has been developed based on the nanoindentation method. Then, the fracturing coefficient K2 is obtained by combining the ratio β of the fracture indentation to the total indentation and the uneven coefficient m. After that, the fracability coefficient K3 is the ratio of the elastic modulus parallel to bedding to that perpendicular to bedding. Finally, the correlation between fracability coefficients K1, K2, and K3 is used to evaluate the overall fracturing performance of shale. The results of this evaluation method are in good agreement with the actual fracturing performance. It can be concluded that this method is highly reliable and practical and well worthy of promoted applications.

CT Analysis Method for Particular Lithology Reservoir Rock

2011 ◽  
Vol 301-303 ◽  
pp. 1372-1377
Author(s):  
Yu Zhou ◽  
He Kun Guo ◽  
Guo Qi Wei ◽  
Yu Juan Zhang
Keyword(s):  
Evaluation Method ◽  
Oil And Gas ◽  
Volcanic Rocks ◽  
Qualitative Evaluation ◽  
Evaluation Criterion ◽  
Reservoir Rock ◽  
Chemical Components ◽  
Core Analysis ◽  
Oil And Gas Exploration ◽  
Ct Analysis

Core analysis is one of the most necessary means to recognize the geological characteristics of reservoirs. Recently, the oil and gas exploration of particular lithology such as volcanic, conglomerate, mud and carbonate rocks continued to make new breakthroughs. As a result, core analysis for particular lithology reservoir rock is increasingly significant. However, conventional methods of core analyzing have great limitations on particular lithology due to the complex chemical components and variable physical status. In order to obtain accurate experimental data and understand the seepage law of particular lithology, advanced core analysis methods are developed through the application of computed tomography (CT). Through the application of nondestructive CT testing for inner construction of core, and the establishing of CT evaluation criterion for the heterogeneity of particular lithology, the goals of analyzing the features and growth of holes and fractures in core and heterogeneity of core are archived. The evaluation criterion is composed by qualitative evaluation and quantitative evaluation, and gives the corresponding evaluation method and formula. The evaluation criterion provides the basis for CT analysis of particular lithology. The application of CT analysis for 211 cores of particular lithology shows: 1) Most conglomerates develops gravel-edge fractures, growth of the fractures is proportional to the level of gravel and inverse proportional to the degree of compaction. Holes in conglomerate are mainly corroding holes between gravel. The growth of holes is related to the composition of cement and compaction. With the lower gravel level, the number of holes and fractures decline. 2) Most volcanic rocks develop holes; some of them develop big holes or lots of holes. Several volcanic samples contain micro-fractures. The growth of holes and fractures in different volcanic rock categories are equivalent, but the type of holes and fractures are different. This research has opened new experimental means for cores of particular lithology. By increasing the skills of core analysis, this research has increased people’s knowledge of reservoir of particular lithology, and means a lot to oil and gas exploration and development.

GEOLOGICAL AND PHYSICAL CHARACTERISTICS OF PRODUCING FORMATIONS AND THEIR ROLE IN OCCURRENCE OF OIL, GAS AND WATER SHOWINGS

2015 ◽  
pp. 117-120
Author(s):  
D. M. Chudnovskii ◽  
V. A. Dolgushin ◽  
J. S. Popova
Keyword(s):  
Oil And Gas ◽  
Physical Characteristics ◽  
The Subject ◽  
Oil Gas

The subject of this study are geological and physical characteristics of productive strata in oil and gas deposits.

scholarly journals Differential characterization of stress sensitivity and its main control mechanism in deep pore-fracture clastic reservoirs

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Denglin Han ◽  
Huachao Wang ◽  
Chenchen Wang ◽  
Wenfang Yuan ◽  
Juan Zhang ◽  
...  
Keyword(s):  
Evaluation Method ◽  
Oil And Gas ◽  
Rapid Change ◽  
Stress Sensitivity ◽  
Irreversible Damage ◽  
Tectonic Zone ◽  
Oil And Gas Fields ◽  
Moderate Change ◽  
Sample Measurement ◽  
Gas Fields

AbstractStress sensitivity in reservoirs is critical during the exploitation of oil and gas fields. As a deep clastic reservoir under strong tectonic compression, the Ahe Formation in the northern tectonic zone of the Kuqa depression exhibited strong stress sensitivity effect. However, the conventional evaluation method by using permeability damage rate as a constraint restricts the mechanistic understanding of the strong stress sensitivity effect. In this study, morphology of stress sensitivity test curve, coupled with rate change of permeability and extent of irreversible damage in actual sample measurement through micro-CT in-situ scanning, is used to characterize differentially. The strong stress sensitivity effects of the studied intervals can be divided into three types: (1) rapid change in permeability–weak irreversible damage, (2) moderate change in permeability–strong irreversible damage and (3) moderate change in permeability–moderate irreversible damage. The strong stress sensitivity is caused by the micro-pores and micro-fractures, which are widely developed in the studied reservoir. The mechanisms caused by the two types of pore are different. The stress sensitivity effects in micro-fracture-rich reservoirs are characterized by rapid change in permeability and weak irreversible damage. Meanwhile, the stress sensitivity effects in micro-pore-rich reservoirs are manifested as moderate change in permeability and strong irreversible damage. The study shows that the differences in the content of micro-pores and micro-fractures and their reverse mechanisms of stress sensitivity co-create different types of stress sensitivity within the samples. Accordingly, the differences of the stress sensitivity type in macroscopic samples are caused by the competition between the microscopic differences of pore types.

Filling process and filling characteristic analysis of Paleogene Baxian sag in Bohai Bay basin, China

2020 ◽  
pp. 1-21
Author(s):  
Zili Zhang ◽  
Xiaomin Zhu ◽  
Ruifeng Zhang ◽  
Sheng Fu ◽  
Jing Zhang
Keyword(s):  
Tectonic Evolution ◽  
Oil And Gas ◽  
Sedimentary Facies ◽  
Flood Plain ◽  
Alluvial Fan ◽  
Evolution Process ◽  
Bohai Bay ◽  
Characteristic Analysis ◽  
Sequence Boundaries ◽  
Lake Basins

In addition to core, logging, and other previous research results, this paper determines the fault development and tectonic evolution process of the Baxian sag with the Paleogene rift stage based on 3D seismic data. The Paleogene tectonic evolution of the sag can be divided into three episodes and six evolution stages, and three types of faults are identified: intensely active normal, active normal, and weakly active normal. One first-order sequence, three second-order sequences, and fourteen third-order sequences of the Paleogene Baxian sag were created, and fifteen sequence boundaries were recognised. According to the rifting background and sedimentary facies development characteristics of each episode, five combination types of the depositional system associations were identified, including alluvial fan-fluvial and braided-delta-lacustrine in an early rifting episode, delta-lacustrine and nearshore subaqueous fan-lacustrine in the middle rifting episode, and fluvial-flood plain in the late rifting episode. Six response models of filling and the evolution process in Paleogene Baxian sag were concluded. The multi-episodes tectonic cycles of faulted lake basins resulted in complex paleogeomorphology and variable provenance supply, forming abundant sequence structure patterns and different filling and evolution processes of faulted lake basins. The stable rifting stage is favourable to form and preserve high-quality source rock, and develop various sedimentary facies and sandbody types, which is a potential area for exploration of a lithologic stratigraphic oil and gas reservoir.

Prevention of Offshore Wind Power Cable Incidents by Employing Offshore Oil/Gas Common Practices

2021 ◽  
Author(s):  
David McLaurin ◽  
Alan Aston ◽  
John Brand
Keyword(s):  
Wind Power ◽  
Oil And Gas ◽  
Early Stage ◽  
Offshore Wind ◽  
Power Cables ◽  
Manufacturing Testing ◽  
Static Conditions ◽  
Offshore Oil ◽  
Oil Gas ◽  
Oil And Gas Sector

Abstract It has been observed that, although submarine power cables have a critical role to wind power arrays and power export to shore, they are often overlooked at early stages of projects and oversimplified during late stages. This leads to lack of attention given during cable design and planning, as well as pressured schedules during manufacturing, testing and installation. The significant number of incidents attributed to offshore submarine cables during construction has increased overall project risk, lowered system average power availability and increased insurance costs. Lack of proper routing can also result in an inability to maintain asset integrity for the project design life. Despite the attention that submarine power cables have received over the past few years, the number and cost of incidents does not appear to be decreasing. A comparison can be made between offshore HVAC and HVDC cables used for wind power and offshore umbilicals and MV cables used in the oil and gas sector. These umbilicals are often similar in weight, size and bending stiffness, and have similar design, manufacturing, routing and installation challenges, but with a fraction of the incidents observed with offshore wind array and export cables. An additional caveat is that the offshore oil and gas sector has achieved a reliable track record while installing and maintaining these umbilicals and cables in fully dynamic conditions (ultra-deep water) as well static conditions. One primary difference between how the oil and gas sector executes these systems are design, planning and specification from an early stage of the project. Significant attention is given at an early stage to quality control, including offshore routing and umbilical testing specifically to avoid incidents resulting in umbilical damage due to the tension and crushing forces during installation as well as ambient seawater and seabed interaction. Management of these risks are documented, and optimal mitigation strategies are implemented early in the design phase. This paper will discuss the types of incidents which have been observed during construction and installation of submarine HVAC/HVDC cables in the wind power sector and how they could have been prevented by normal practices of the offshore oil/gas sector from early design and planning all the way to installation and commissioning.

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