Logging Methods Research Articles

A unified approach to three-dimensional modeling of the logging process by galvanic and induction probes in anisotropic media

The article considers a unified approach to modeling logging probes with both galvanic and induction electric field sources. This approach is based on the properties of the functional spaces used in the finite element method and allows for a single software implementation for various logging methods. As an example of the use of the proposed approach, the logging process in an anisotropic medium with a slope of the main axes of anisotropy is considered.

Contribution of temperature measurements to the hydrogeological model in the Snowy 2.0 deep tunnels

This paper refers to experiments developed on the deep tunnels design of the Snowy 2.0 pumped-storage hydroelectric project in NSW, Australia. The 27 km long waterway and the power station complex are about 800 m below ground, and are in a complex tectonic and lithological setting. Long-term temperature monitoring in boreholes has been used to infer an empirical thermal model along the deep tunnels, which is presented as an example of input data for the ventilation design during construction, and for durability design during operation. An innovative aspect of this paper is related to the graphical interpretative method of borehole temperature logs that is proposed to infer downward or upward groundwater flows and predict the hydrogeological behaviour of fractured and faulted zones that cross the tunnel alignment. A large campaign of thermal acquisition in boreholes, using an acoustic televiewer probe, identified local anomalies of the geothermal gradient, which were correlated to permeability and pressure data measured in the boreholes, to identify zones of greater permeability that intersect the tunnels. Furthermore, the application of thermal measurements during tunnel excavation is proposed as an additional tool for the prediction of water inflow or identification of zones to be pre-grouted and/or drained. Thematic collection: This article is part of the Leading to Innovative Engineering Geology Practices collection available at: https://www.lyellcollection.org/topic/collections/leading-to-innovative-engineering-geology-practices

Use of machine learning technology to model the distribution of lithotypes in the Permo-Carboniferous oil deposit of the Usinskoye field

Permo-Carboniferous oil deposit of the Usinskoye field is characterized by an extremely complex type of the void space with intense cross-sectional distribution of cavernous and fractured rock. In this study, for this production site, the process of 3D geological modeling has been implemented. At the first stage, it provided for automated identification of reservoir volumes by comparing the data of core and well logging surveys; at the second stage, identification of rock lithotypes according to Dunham classification is performed on the basis of comparison of thin sections examination and well logging data. A large array of factual information enables the use of machine learning technology on the basis of Levenberg – Marquardt neural network apparatus toward achievement of our research goals. The prediction algorithms of reservoir and rock lithotype identification using well logging methods obtained on the basis of the training samples are applied to the wells without core sampling. The implemented approach enabled complementing the 3D geological model with information about rock permeability and porosity, taking into account the structural features of the identified lithotypes. For the Permo-Carboniferous oil deposit of the Usinskoye field, the volumetric zoning of the distribution of different rock lithotypes has been established. Taking into account the lithotypes identified based on machine learning algorithms, density and openness of fractures were determined, and fracture permeability in the deposit volume was calculated. In general, during the implementation, the machine learning errors remained within 3-5 %, which suggests reliability of the obtained predictive solutions. The results of the research are incorporated in the existing 3D digital geological and process model of the deposit under study.

Comparing Vs profiles from MASW and downhole logging method from glacial deposits in central Illinois

Comparing Vs profiles from MASW and downhole logging method from glacial deposits in central Illinois

Correction of Light and Heavy Hydrocarbons and Their Application in a Shale Oil Reservoir in Gaoyou Sag, Subei Basin—A Case Study from Well SX84

To accurately evaluate the shale oil resources in the Funing Formation of the Gaoyou Sag, Subei Basin, light and heavy hydrocarbon correction models of S1 were developed based on the rock pyrolysis of liquefrozen, conventional, and oil-washed shales. The improved ΔlogR technique was applied to establish the TOC, S1, and S2 logging evaluation methods. The results showed that the S2 values after oil washing were significantly lower than before. The difference between these two S2 (ΔS2) values is the heavy hydrocarbon correction amount of S1, which is about 0.69 S2. There was almost no loss of light hydrocarbons during liquefrozen shales’ pyrolysis tests; the ratio of liquefrozen to conventional S1 values is the light hydrocarbon correction factor, which is about 1.67. The corrected S1 is about 3.2 times greater than the conventional shale-tested value. The S1 and TOC are obviously “trichotomous”; a TOC greater than 1.5% and corrected S1 larger than 4.0 mg/g corresponds to the enriched resource. The logging estimated results show that the total shale oil resources in the E1f2 of the Gaoyou Sag are about 572 million tons, of which the enriched resource is about 170 million tons.

The double-edged sword effect of employee impression management and counterproductive work behavior: From the perspective of self-control resource theory.

Why do people who seem to be doing well in the workplace occasionally behave badly? Because these employees may be using impression management tactics to create an image. Existing studies have focused on comparing the differences in the use of impression management among different individuals, but cannot explain why a well-behaved individual sometimes behaves badly. Based on the theory of self-control resources, we adopts the survey method of job logs and collects the data of 121 employees. The results show that: (1) the use of self-promotion tactics and ingratiation tactics will promote the depletion of self-control resources. (2) The depletion of self-control resources will encourage employees to engage in counterproductive work behaviors. (3) The effect of self-promotion tactic and ingratiation tactic on the depletion of self-control resources was moderated by emotional intelligence. In the case of high emotional intelligence, this effect is attenuated. And vice versa. (4) Under high emotional intelligence and low emotional intelligence, the indirect effects of self-promotion tactic and ingratiation tactic on employees' counterproductive work behaviors are significantly different. Our research breaks through the between-individual perspective and illustrates the double-edged sword effect of self-promotion tactic and ingratiation tactic on employee counterproductive work behavior and its mechanism from the internal perspective, which is highly innovative.

A Time and Motion Study of Community Health Workers in Rural Area of Ballabgarh, Haryana.

Health workforce is the important pillar of health system in India. Efficient utilization of scarce community-level human resources in health care is critical to ensure optimum care in a community. To describe the time utilization pattern of health workers (HWs) during field activity at the primary healthcare level and to study the facilitators and barriers in efficient time utilization. A mixed-method study with a time and motion approach was carried out in the rural areas of Ballabgarh block of Haryana. Time and motion approach was continuous, direct, synchronous and both active and passive method of time logging was adapted. Electronic Geo-Positioning System based mobile, timestamp application and the digital stopwatch were used to capture time utilization. The quality of the data collected in the daily work plan during the household (HH) visits was assessed using semi-structured interview schedule. In-depth interview with the HWs was carried out to understand the facilitating factors and barriers in their efficient functioning. Proportion of HH s covered in data collection for time and motion patterns was 36% out of the total number of HH s in the SCs. The completeness of work plan was 74.8%. The average number of HHs covered per day by an HW was 38. Mean (standard deviation [SD]) time duration spent in each HH in completing the work plan was 2.9 (0.8) minutes. Mean (SD) total distance travelled by HW per day was 1845.1 (974.2) metres. Mean (SD) time duration spent idle in the field was 22.7 (13.0) minutes. Proportion of effective time utilised in the field was 54.3%. Several enabling factors and barriers were identified at personal, community, and health system level. Only half of the allotted time was effectively utilized by the HWs for house visit in the community. Planning the beat schedule as per the feasibility and ensuring quality of HH visits using information technology is critical for providing primary healthcare at village level.

Determination of groundwater potential using electrical resistivity survey and borehole logging in sites I and III of Delta State University, Abraka Nigeria

This study examines the aquifer properties and lithological structure of Abraka, Nigeria, specifically the Delta State University Site I and III environs. Ten Schlumberger geoelectric soundings, geophysical well logging and pumping test method were employed using an ABEM Terrameter. A drilled water well and existing borehole data were used for this study. The result of the lithological study revealed that the subsurface formations consist of topsoil, lateritic sand, fine and medium grain sand mixed with clay. The topsoil is brownish with thickness of 2 m, the laterite is reddish with thickness of 4 m, the fine sand is whitish with thickness of 10 m, and the medium sand is also whitish with thickness >12 m. The results of the evaluation of the geoelectric data using curve matching and Win Resist computer iteration was in strong agreement with that of the well record, with a subsurface that is composed of 4 to 6 geo-electric layers. The depth ranges from 13.5m to 97.8m while the resistivity ranges from 1021.2 Ωm to 9092.4 Ωm. A core soil sample collected at an interval of 5m, spontaneous potential and resistivity logs were carried out on the well. The hydraulic conductivity, well's transmissivity, storativity, and specific capacity are 102.7m2/day, 5.14 m/day, 0.00062 and 0.39 m3/m respectively. It is recommended that a drill depth of 30 m and above should be accessed for potable water in the area. From the result of this survey, we infer that this aquifer is confined and capable of supplying the people with adequate and good quality drinking water.

Extracting mud invasion information using borehole radar — A numerical study

In hydrocarbon drilling, mud filtrate penetrates permeable formations and alters the pore fluid characteristics in the immediate vicinity of the borehole. Typically, the prevailing in situ pore fluids are displaced by the invading mud filtrate, which leads to gradually changing distributions of the fluid and electrical properties. Understanding this invasion process is crucial for the interpretation of logging data and associated reservoir evaluations. Conventional logging methods tend to be inadequate for this purpose as their resolution is too low. We find that invasion depth can be determined from borehole radar data using an optimized antenna configuration and time-lapse measurements. A series of parametric sensitivity analyses provide information about the effects of variations of the rock and fluid properties on the identification and extraction of borehole radar signals reflected from the invasion front. Our results suggest that by embedding the radar antennas in cavities filled with an absorbing dielectric material, it is possible to minimize the interference arising from the metal components of the logging tool. In the simulated reservoir scenario, a time-lapse measurement mode with a time interval of at least 6 h can reliably extract the radar signals reflected from the invasion front, and the proposed borehole radar has a lateral detection range from 0.15 to 1 m. A comprehensive range of parametric sensitivity analyses indicates that the signals reflected from the invasion front are principally influenced by oil viscosity, porosity, and mud and formation water salinity, as well as by molecular diffusion coefficient and cementation exponent. These properties and parameters should be carefully explored and assessed when applying borehole radar to evaluate mud invasion information in a reservoir environment.

Precise method for measuring soil carbon

The paper focuses on adapting some nuclear logging methods for in-situ evaluation of carbon content in soil. A set of methods and related instrumentation for soil survey are proposed. The quantitative characteristics of soil properties and composition are derived from Monte Carlo simulation of detector response. The study suggests a step-by-step procedure with an emphasis on estimation of low concentration of carbon.

TOC interpretation of lithofacies-based categorical regression model: A case study of the Yanchang formation shale in the Ordos basin, NW China

In this paper, taking the shale of Chang 7-Chang 9 oil formation in Yanchang Formation in the southeastern Ordos Basin as an example, through the study of shale heterogeneity characteristics, starting from the preprocessing of supervision data set, a logging interpretation method of total organic carbon content (TOC) on the lithofacies-based Categorical regression model (LBCRM) is proposed. It is show that: 1) Based on core observation, and Differences of sedimentation and structure, five lithofacies developed in the Yanchang Formation: shale shale facies, siltstone/ultrafine sandstone facies, tuff facies, argillaceous shale facies with silty lamina and argillaceous shale facies with tuff lamina. 2) The strong heterogeneity of shale makes it difficult to accurately explain the TOC distribution of shale intervals in the application of model-based interpretation methods. The LBCRM interpretation method based on the understanding of shale heterogeneity can effectively reduce the influence of formation factors other than TOC on the prediction accuracy by studying the characteristics of shale heterogeneity and constructing a TOC interpretation model for each lithofacies category. At the same time, the degree of unbalanced distribution of data is reduced, so that the data mining algorithm achieves better prediction effect. 3) The interpretability of lithofacies logging ensures the wellsite application based on the classification and regression model of lithofacies. Compared with the traditional homogeneous regression model, the prediction performance has been greatly improved, TOC segment prediction is more accurate. 4) The LBCRM method based on shale heterogeneity can better understand the reasons for the deviation of the traditional model-based interpretation method. After being combined with the latter, it can make logging data provide more useful information.

Investigation of volcanic rock quantitative fracture evaluation and reservoir classification based on the logging method - an example from Nanpu Sag

Investigation of volcanic rock quantitative fracture evaluation and reservoir classification based on the logging method - an example from Nanpu Sag

Investigation of volcanic rock quantitative fracture evaluation and reservoir classification based on the logging method - an example from Nanpu Sag

Multi-stage development results in complex lithology and variable pore structure in volcanic reservoirs. Therefore, it is difficult to calculate fracture porosity and determine the volcanic reservoir type. In this study, we use the deep volcanic rock of the Nanpu No. 5 structure as an example to use a matrix porosity logging evaluation model in different lithology reservoirs. Dual Laterolog has a large detection range and is sensitive to fractures. Therefore, the relationship between igneous fracture and logging response characteristics is analysed via numerical simulation. Then, the method used for calculating fracture parameters was verified by combining formation MicroScanner image (FMI) logging technology with Dual Laterolog. For accurate reservoir classification, a fracture porosity less than 0.0005 is ineffective since the formation fluid cannot be transported. The quantitative fracture evaluation of volcanic rock reservoir was completed based on calculation model. The agreement with the actual production proved the effectiveness of the method. [Received: September 9, 2022; Accepted: December 30, 2022]

May the force be with you: an investigation into logging methods using donkeys

Working equids represent major sources of energy worldwide, and assume an increasingly important role in line with increasing requirements for sustainable energy. The effectiveness of their contributions relies on welfare, especially in the case of donkeys that, due to their size, face more adverse working conditions compared to larger equids. In this study, heart rate and force exerted were monitored while logging using three methods: direct pull, sled, and vehicles. A swingle tree incorporating a dynamometer and data logger was developed for this project, allowing continuous recording of forces. It was hypothesized that logging techniques that suspend (partially or totally) the load from the ground, reduce the force exerted, thus reducing physical effort. This study also aimed to understand if heart rate can be used as an alternative proxy measure when pulling different loads using different methods. Results showed that the greatest force was measured during direct pull (369.66 N), requiring 20% greater force compared to the sled (299.10 N, P <0.001), and 60% greater force than the vehicle (125.11 N, P <0.001). The sled required an additional 58% of force compared to the vehicle (P <0.001). This determines vehicles are the best option for reducing the force exerted by donkeys. Affordability and skills needed to work with this technique, however, are important considerations. Sleds represent a user-friendly solution; reducing the force needed when compared to direct pull, requiring less skills and equipment. The dynamometer proved an excellent method for force monitoring. Heart rate as a proxy measure for force didn’t provide accurate data for lighter loads. Increasing load weight, followed by the increasing force requirements, correlation and explanatory power became greater, indicating that with heavier logs, or methods that display greater force requirements, heart rate may be used as a proxy method for force, but further studies are needed.

Summary of research methods for porosity and permeability of coalbed methane reservoir

In order to serve the research on the physical properties of coalbed methane reservoirs and improve the prediction effect of porosity and permeability of coal reservoirs, this paper, based on a large number of literature research, summarizes the concepts, influencing factors and prediction methods of coal seam porosity and permeability. The research shows that the main factors affecting the porosity of coalbed methane reservoir are coal petrographic composition, metamorphic degree, coal body structure and buried depth, compaction, tectonism, etc; The main influencing factors of permeability include component content, coal rank, coal body structure and in-situ stress, buried depth of coal seam, natural fracture of coal seam, matrix shrinkage, Klinkenberg effect, etc. The porosity prediction of coalbed methane reservoir generally adopts true and apparent relative density method, in addition, there are multiple regression method based on logging information, nuclear magnetic resonance logging method, etc; The measurement methods of CBM reservoir permeability mainly include the calculation method based on conventional logging, triaxial stress experimental research method, joint prediction method of nuclear magnetic resonance and electrical imaging logging, dynamic data analysis method and numerical simulation method. The development of coal seam porosity and permeability prediction technology needs innovative breakthroughs in hardware and software.

Fine structure interpretation and reservoir forming characteristics analysis of Jurassic Badaowan Formation in Madong area of Xiayan fault zone

Fine structural interpretation is one of the effective methods to find favorable structural traps and targets. Aiming at the fault interpretation of Jurassic Badaowan Fm in Madong area of Xiayan fault zone is not fine and structural characteristics are not implemented, the structural characteristics of Jurassic Badaowan Fm are implemented and favorable traps are found through the study of seismic, well logging and geological comprehensive methods. The results show that the structure of Jurassic Badaowan Fm in Madong area is high in the north and low in the south. The first member of Badaowan Fm is a delta front subaqueous distributary channel deposit, which is a hydrocarbon enrichment zone. Oil and gas are adjusted along the relay of deep and shallow faults, and the great fault zone and the inherited uplifting zone are favorable accumulation areas of Jurassic Badaowan Fm in Madong area. In this paper, the relationship between deep and shallow fault system and hydrocarbon distribution of Badaowan Fm in Madong area is systematically reviewed for the first time. Combined with the palaeohigh distribution, three favorable hydrocarbon accumulation zones are identified, which provides favorable targets for exploring the hydrocarbon accumulation potential of Badaowan Fm.

Practical Application of Geophysical Logging in Coalbed Methane Exploration and Development

Geophysical logging technology is indispensable in resource development and reservoir evaluation. Through logging curves, physical characteristics of formation lithology can be accurately reflected, so as to effectively solve geological problems. It can not only be used to explain and evaluate the geological parameters of coalbed methane in a single well, but also to comprehensively evaluate the indicators of coal seam physical property and gas content in this area. With the development of social science and technology, logging technology is constantly improved, increasing the research on logging technology and methods is very beneficial to the exploration and development of coalbed methane. Based on this, this paper focuses on geophysical logging analysis and discusses its practical application in coalbed methane exploration and development.

Improving the efficiency of putting oil deposits with hard-to-recover reserves of Western Siberia into development

The article shows that reservoirs of various genesis generalization into one petrophysical model using core intervals with the best filtration-capacitance properties leads to an overestimation of boundary values and a decrease in the resource potential of thin-layered and low-permeable facilities. Additional core sampling and dependencies revision using radioactive logging methods allowes us to take a fresh look at the facility, at the same time, the initial geological reserves increase by more than half and justify the status of hard-to-recover reserves, thereby increasing its attractiveness for commissioning initial geological reserves by more than half and justifying the status of hard-to-recover reserves, thereby increasing its development attractiveness. To improve the technical and economic assessment, the transition to a development system based on horizontal wells with multi-stage hydraulic fracturing was justified, and the optimal parameters for the well grid density, their completion, and the reservoir pressure maintenance system organization were determined. The use of the recommendations makes it possible to increase the oil recovery factor and the net present value of the project by more than two times compared to the baseline approved option. Keywords: hydraulic fracturing; hard-to-recover reserves; geomechanical model; development efficiency improvement; shale; low permeable reservoir.

Методика расчета параметров механических свойств горных пород для моделирования гидроразрыва пласта

Introduction. The inability to accurately predict the hydraulic fracturing gradient (fracking) occasionally leads to catastrophic consequences, for example, to the disclosure of natural cracks in the object, which was not planned. It results in very expensive problems during the construction of the well. The hydraulic fracturing gradient is an extremely important parameter that needs to be taken into account when designing the well wiring. Materials and research methods. To simulate hydraulic fracturing, laboratory complexes are often used, where experimental studies of rock samples taken in the well are carried out. The article presents a scheme for determining the propagation velocity of longitudinal and transverse waves in laboratory conditions in order to calculate the Poisson’s ratio. Research results and their discussion. The system works by exciting an ultrasonic acoustic wave at the end of a cylindrical core sample, followed by recording the arrival times of waves at the end of the core end. Knowing the length of the core sample, the velocities of the longitudinal and transverse waves are calculated. The velocity is equal to the ratio of the length of the sample to the time of arrival of the wave at the opposite end of the sample. However, often core samples taken from the well in which it is planned to perform hydraulic fracturing are not always representative, often in practice there is a low percentage of core sampling. The article presents a method for calculating some initial parameters for modeling hydraulic fracturing, based on field and geophysical data. The calculation includes the application of a comprehensive analysis of the data of geophysical studies of wells by broadband acoustic logging and the results of numerical calculations of the physical and mechanical properties of rocks. Conclusions. The information obtained allows one to quickly and efficiently perform the necessary calculation of the strength properties of the walls of the well, perform hydraulic fracturing efficiently, determine the characteristics of the elastic medium practically on a real-time scale, as well as design other technological processes using the fundamental laws of underground hydrodynamics and analysis of the results of geological and field studies. It should be noted that in the absence of logging material by the broadband acoustic logging method, it is proposed to use the data of standard acoustic logging, the implementation of which is regulated in all wells during their construction, and through it to calculate the speed of the transverse wave run based on tabular values of the velocities of longitudinal and transverse waves in rocks.

КОМПЛЕМЕНТАРНОСТЬ МЕТОДОВ ИМПУЛЬСНОГО НЕЙТРОННОГО КАРОТАЖА И ЭЛЕКТРИЧЕСКОГО ДИВЕРГЕНТНОГО КАРОТАЖА В ОБСАЖЕННЫХ СКВАЖИНАХ

In production wells, nuclear-physical and electrical logging methods are used to study the backwater space. More well-known and widespread is pulsed neutron logging (PNL) [16] and its modifications. Electric divergent logging (EDC) is considered less common [2] in cased wells. Both methods solve the same problem, but they are still not ideal and have their drawbacks. This article presents the advantages and disadvantages of the PNL and EDC methods in comparison with each other. A significant criterion when choosing the preferred method for determining the current oil and gas saturation is the minimum error of the output results of the study by the method. The operating conditions of a particular deposit must be taken into account. When choosing the optimal method for determining the current oil and gas saturation from the point of view of the minimum error, the operating conditions of each specific field should be taken into account. The best results, however, will obviously be achieved by combining the above methods, which radically differ significantly both in their physical characteristics and in the principles of measuring nuclear physical and electrical parameter.