scholarly journals Analyzing the Origin of Low Resistivity in Gas-Bearing Tight Sandstone Reservoir

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Yanjiao Jiang ◽  
Jian Zhou ◽  
Xiaofei Fu ◽  
Likai Cui ◽  
Chao Fang ◽  
...  

Complex characteristics exist in the resistivity response of Gs reservoirs in the central inversion belt of the Xihu Sag, East China Sea Basin. Some drilling wells have confirmed the existence of abnormally low resistivity in gas reservoirs of the area; and the electrical logging response was unable to reflect fluid properties of the reservoir accurately. Therefore, it is necessary to analyze the origin of the low resistivity and determine its controlling factors. Based on experimental data of core analysis and numerical simulations of mud invasion, this study thoroughly explores the origin of low resistivity in the subject gas-bearing reservoir considering both internal and external factors. The results indicated that when there is no or a low degree of mud invasion, the fine lithology, complex pore structure, additional clay mineral conductivity, and high content of pyrite are the main internal factors driving the conditions present in the studied gas reservoir. When mud invasion occurs, the invasion of highly saline mud is the main external cause of low resistivity. The numerical simulation results indicated that a formation with good permeability and high overbalance pressure has a deep invasion depth. The resistivity around the well is obviously reduced after the invasion, and low resistivity would form easily. Combined with actual data of several wells, the main influencing factors of the reservoir’s electrical characteristics were analyzed, and the main controlling factors of low resistivity in the gas reservoirs are given. This study provides valuable support for studying the low-contrast complex reservoir conductivity mechanism. The study also offers novel ideas for accurate calculation of saturation and the meticulous evaluation of reservoir for subsequent studies.

2020 ◽  
Vol 17 (3) ◽  
pp. 463-474
Author(s):  
Shengjie Li ◽  
Ying Rao

Abstract Seismic low-frequency amplitude shadows have been widely used as a hydrocarbon indicator. This study investigates the effect of reservoir properties and seismic wave mode conversion on the characteristics of the low-frequency amplitude shadows in gas-bearing reservoirs. The target gas reservoirs are typically related to the lithology of tight sandstone with strong heterogeneity. Pore-fluid distribution within the reservoirs presents patchy saturation in the vertical and horizontal directions, and this patchy saturation easily induces low-frequency shadows beneath gas-bearing reservoirs. These low-frequency shadows are validated by using a poroelastic simulation method. The results of our field case-based study indicate that pore-fluid property, plus the thickness and heterogeneity of reservoirs are the key elements in the generation of low-frequency shadows. The results also indicate that the poroelastic simulation method can be used to effectively predict the spatial distribution of gas-bearing reservoirs, by directly verifying the low-frequency shadow phenomenon existing in the seismic data.


2019 ◽  
Author(s):  
Onsardi Onsardi

The title of this study is the Strategy of Increasing Consumer Food Loyalty in CurupCity, Rejang Lebong Regency (Case Study in "Henvian" Typical Food Industry). Thisresearch is based on the importance of strategies in increasing business and consumerloyalty to products sold.Strategies to increase business and consumer loyalty can bedone with a SWOT analysis. Place of this research is the "Henvian" shop that sellstypical Rejang lebong food. The method used in this study is descriptive qualitative.Informants in this study were people who were considered to know for certain about theHENVIAN Specialty Food Store in Curup City, Rejang Lebong Regency. The dataanalysis technique used in this study is a SWOT analysis to determine the strengths,weaknesses, opportunities and threats in a typical Rejang Lebong food business.By using SWOT analysis techniques that consist of strengths (weakness), weaknesses(weakness), opportunities (opportnity) and threats (threath). The results of this studycan be concluded that the internal factors that are the strength of the marketing strategyare the quality of the product that is good at a price affordable to the public andtourists, service that is friendly and responsive to consumer needs, as well astechnological advancements that facilitate the promotion of business. Internal factorsthat are a weakness are often lack of stock, there are some products that do not meet thestandard packaging, the product shelf life is short, employees do not use uniforms.External factors that become opportunities are a fairly high economic community,abundant raw materials while external factors that are a threat are the manycompetitors, an unstable economy, the price of basic needs increases. Based on theresults of the SWOT analysis of internal and external factors, the strategy used is toimprove product quality by improving the appearance of packaging and quality ofcontent and quality of service by providing uniforms to employees and providingstandards of service to consumers. .Keywords: Strategy, Consumer Loyalty, SWOT


2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Mendah Nur Kumala ◽  
Mei Santi ◽  
Hasan Sultoni

One alternative to reduce the unemployment rate in Indonesia is to foster entrepreneurship in college students because this is expected to be an educated young entrepreneur who is able to start his own business, and be able to open up jobs for others. The formulation of the problem include: what are internal factors (income, self-esteem, motivation) and whether external factors (family environment, surrounding environment, education, and opportunities) influence the interest in entrepreneurship of STAI Muhammadiyah Tulungagung students ?. This study aims to determine internal factors (income, self-esteem, motivation) and external factors (family environment, surrounding environment, education, and opportunities) affect the entrepreneurial interest of STAI Muhammadiyah Tulungagung students. The approach used is a quantitative approach to the type of associative research. The population and sample in this study were students of STAI Muhammadiyah Tulungagung which consisted of 50 students who had taken Entrepreneurship courses and students who had been entrepreneurs. Sampling using a purposive sampling technique. The data source is primary data. Data collection was carried out through questionnaires. The measurement uses a Likert scale. The next stage, the results of the questionnaire were analyzed with multiple linear regression which serves to prove the research hypothesis. The data that has met the validity test, reliability test, and the classic assumption test are processed to produce a regression equation. Based on the results of the study showed that internal and external factors partially had a positive and significant effect on the entrepreneurial interest of STAI Muhammadiyah Tulungagung students. With an adjusted R2 value of 0.407 so the magnitude of the influence of internal and external factors on entrepreneurial interest is 40.7% while the remaining 59.3% is influenced by other factors not examined in this study.Keywords: Factors, Interests, Entrepreneurship, STAI Muhammadiyah Tulungagung


2021 ◽  
Author(s):  
Yessica Fransisca ◽  
Karinka Adiandra ◽  
Vinda Manurung ◽  
Laila Warkhaida ◽  
M. Aidil Arham ◽  
...  

Abstract This paper describes the combination of strategies deployed to optimize horizontal well placement in a 40 ft thick isotropic sand with very low resistivity contrast compared to an underlying anisotropic shale in Semoga field. These strategies were developed due to previously unsuccessful attempts to drill a horizontal well with multiple side-tracks that was finally drilled and completed as a high-inclined well. To maximize reservoir contact of the subject horizontal well, a new methodology on well placement was developed by applying lessons learned, taking into account the additional challenges within this well. The first approach was to conduct a thorough analysis on the previous inclined well to evaluate each formation layer’s anisotropy ratio to be used in an effective geosteering model that could better simulate the real time environment. Correct selections of geosteering tools based on comprehensive pre-well modelling was considered to ensure on-target landing section to facilitate an effective lateral section. A comprehensive geosteering pre-well model was constructed to guide real-time operations. In the subject horizontal well, landing strategy was analysed in four stages of anisotropy ratio. The lateral section strategy focused on how to cater for the expected fault and maintain the trajectory to maximize reservoir exposure. Execution of the geosteering operations resulted in 100% reservoir contact. By monitoring the behaviour of shale anisotropy ratio from resistivity measurements and gamma ray at-bit data while drilling, the subject well was precisely landed at 11.5 ft TVD below the top of target sand. In the lateral section, wellbore trajectory intersected two faults exhibiting greater associated throw compared to the seismic estimate. Resistivity geo-signal and azimuthal resistivity responses were used to maintain the wellbore attitude inside the target reservoir. In this case history well with a low resistivity contrast environment, this methodology successfully enabled efficient operations to land the well precisely at the target with minimum borehole tortuosity. This was achieved by reducing geological uncertainty due to anomalous resistivity data responding to shale electrical anisotropy. Recognition of these electromagnetic resistivity values also played an important role in identifying the overlain anisotropic shale layer, hence avoiding reservoir exit. This workflow also helped in benchmarking future horizontal well placement operations in Semoga Field. Technical Categories: Geosteering and Well Placement, Reservoir Engineering, Low resistivity Low Contrast Reservoir Evaluation, Real-Time Operations, Case Studies


2020 ◽  
Vol 10 (9) ◽  
pp. 2003-2012
Author(s):  
O.V. Karpets ◽  
◽  
A.V. Sinitsyn ◽  
A.V. Firsova ◽  
◽  
...  

This article discusses the problem of choosing the correct and effective organizational structure of enterprise management for its correct functioning. The existing types of organizational structures of enterprise management, which are used in practice today, are analyzed, and their positive, negative sides and the type of enterprises for which they can be used are revealed. Along with this, this article discusses and describes methods for choosing an organizational structure for an enterprise. Also, during the study, internal and external factors were identified that affect the choice of an organizational structure. Based on the analysis, a methodology for choosing the most effective type of organizational structure for enterprises was drawn up. The question of choosing an organizational structure is acute for every manager at the very beginning of the operation of an enterprise, because the quality of performance of functions, both of individual divisions and of the entire enterprise as a whole, directly depends on this. Among many types of organizational structures in this study, the types of organizational structures that are most adaptable to changes in external and internal factors are identified. This study provides methods and tools for selecting the appropriate organizational structure for any enterprise. At the moment, some methods, be it goal structuring or computer modeling, are not widely used, which in turn makes it difficult to choose an effective organizational structure for enterprise management. The choice of an effective organizational structure is an extremely urgent problem today for every entrepreneur, who is interested in the stable economic activity of his or her enterprise.


2021 ◽  
Author(s):  
Ramsin Eyvazzadeh ◽  
Abdullatif Al-Omair ◽  
Majed Kanfar ◽  
Achong Christon

Abstract A detailed description of a modified Archie's equation is proposed to accurately quantify water saturation within low resistivity/low contrast pay carbonates. The majority of previous work on low resistivity/low contrast reservoirs focused on clastics, namely, thin beds and/or clay effects on resistivity measurements. Recent publications have highlighted a "non-Archie" behavior in carbonates with complex pore structures. Several theoretical models were introduced, but new practical applications were not derived to solve this issue. Built upon previous theoretical research in a holistic approach, new models and workflows have been developed. Specifically, utilizing a combination of machine learning algorithms, nuclear magnetic resonance (NMR), core and geological data, field specific calibrated equations to compute water saturation (Sw) in complex carbonate formations are presented. Essentially, these new models partition the porosity into pore spaces and calculate their relative contribution to water saturation in each pore space. These calibrated equations robustly produce results that have proven invaluable in pay identification, well placement, and have greatly enhanced the ability to manage these types of reservoirs. This paper initially explains the theory behind the development of the analysis illustrating workflows and validation techniques used to qualify this methodology. A key benefit performing this research is the utilization of machine-learning algorithms to predict NMR derived values in wells that do not have NMR data. Several examples explore where results of this analysis are compared to dynamic testing, formation testing and laboratory measured samples to validate and demonstrate the utility of this new analysis.


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