scholarly journals Section types and oil prospects of the Bazhenov Formation in the Nadym-Ob interfluve

Georesursy ◽  
2020 ◽  
Vol 22 (3) ◽  
pp. 2-11
Author(s):  
Mikhail A. Fomin ◽  
Rashid M. Saitov

The article presents the results of studying the geological structure of the Bazhenov Formation in the Nadym-Ob interfluve of Western Siberia with the aim of predicting the oil content of this black shale stratum. As a result of interpretation of a wide range of well logging represented by electric, radioactive and acoustic logging, with subsequent matching of these results with paleontological definitions of micro- and macrofauna, the distribution of the Salym, Nizhnevartovsky and Tarkosalinsky types of sections of the Bazhenov Formation was clarified, transitional areas between them were identified. It has been established that the Tarkosalinsky type is more widespread in the western direction than was shown earlier and is also distinguished in the Vengayakhinskaya, Yaraynerskaya and other areas. The Nizhnevartovsky type, on the contrary, has a narrower distribution and stands out directly within the same name arc and to the south by the Variegasky-Tagrinsky megahigh. On the basis of geological, geochemical, geophysical criteria and the results of an inflow test in deep wells, a map of the oil potential prospects of the “classical” sections of the Bazhenov Formation has been compiled. Regional prerequisites (high catagenesis of organic matter, significant modern concentrations of organic carbon, etc.) for the discovery of industrial accumulations of oil in the Bazhenov Formation in the southern regions of the Yamalo-Nenets Autonomous Area are identified. The results of the test for the inflow of the Bazhenov Formation in this area in the 70–90s XX century were analyzed; repeated, interval testing of these deposits using modern methods of stimulation of the inflow is recommended. The necessity of laboratory lithological, petrophysical, geochemical study of the core of the Bazhenov Formation in the southern part of the Yamalo-Nenets Autonomous Area is substantiated with the aim of determining its lithological composition, identifying oil source and oil productive intervals, studying the reservoir structure and the nature of saturation of its void space, developing recommendations for calculating oil reserves and creating technology for its cost-effective production.

Geosciences ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 269
Author(s):  
Olga V. Postnikova ◽  
Alexander V. Postnikov ◽  
Olga A. Zueva ◽  
Artem E. Kozionov ◽  
Ekaterina V. Milovanova ◽  
...  

The deposits of the Bazhenov formation are a unique reservoir of unconventional oil reserves in Western Siberia. They contain both solid organic matter (kerogen) and liquid light oil. The successful development of these hydrocarbons is largely determined by the adequacy of the void space models. The aim of the study is to identify the types of void space in the sediments of the Bazhenov formation and to identify the distribution patterns across the section of the researched wells. The void space was studied by electron and optical microscopy, and the mineral composition of the rocks was determined by X-ray diffraction analysis. The deposits of the Bazhenov productive formation in the territory of Western Siberia are represented by a wide complex of lithotypes, including various kinds of silicites, carbonate, clay rocks, and mixtites. The reservoir space in the reservoir rocks of the Bazhenov formation is a complex and hierarchically subordinated system, which includes voids and fractures of various sizes, configurations, and genesis. The void space of the Bazhenov formation is characterized by a fairly high degree of spatial heterogeneity, which is controlled by lithological, facies, and tectonic factors, as well as the direction of catagenetic processes.


Author(s):  
L.S. Kuleshova ◽  
◽  
I.G. Fattakhov ◽  
Sh.Kh. Sultanov ◽  
R.U. Rabaev ◽  
...  

The paper presents the possibilities of expanding production opportunities in the oil company PJSC Tatneft. For this purpose, the well No.xxx7g with an inclined pilot borehole was drilled at the Bavlinskoye oil field and oriented core samples were taken to study the lithological cross-section and the geological structure of the subsurface horizons. The horizontal wellbore itself is located in the dankovo-lebedyansky horizon, where multi-zone hydraulic fracturing was carried out through ports with packers there. The following methods will increase the share of recoverable oil reserves in the oldest oil-producing Volga region by starting the development of new productive horizons and increase the oil recovery factors for these reservoirs. The methods used in this work will reduce the unit costs of increasing oil production and achieve a cost-effective level of work on wells of this type. The work had its own peculiarities. One of the reasons for the difficulty in interpreting the hydraulic fracturing Minifrac (Meyer software package) was the rather long time of closing fractures in domanic deposits during the registration of pressure drop. In turn, during the minifrac analysis of the Nolte G Time Test graph showed that the fracture did not close, and therefore it is impossible to determine the closing pressure (the pressure gradient of the gap) with reliable accuracy. Note that when interpreting the flow test results, the best match of the experimental and calculated curves is achieved when using the model of a horizontal well operating a homogeneous reservoir. Also, the deterioration of the bottom-hole zone may be associated with a weak opening of the created fractures. Keywords: oil; well; hydraulic fracturing; unconventionals; fracture; core.


2020 ◽  
pp. 1192-1198
Author(s):  
M.S. Mohammad ◽  
Tibebe Tesfaye ◽  
Kim Ki-Seong

Ultrasonic thickness gauges are easy to operate and reliable, and can be used to measure a wide range of thicknesses and inspect all engineering materials. Supplementing the simple ultrasonic thickness gauges that present results in either a digital readout or as an A-scan with systems that enable correlating the measured values to their positions on the inspected surface to produce a two-dimensional (2D) thickness representation can extend their benefits and provide a cost-effective alternative to expensive advanced C-scan machines. In previous work, the authors introduced a system for the positioning and mapping of the values measured by the ultrasonic thickness gauges and flaw detectors (Tesfaye et al. 2019). The system is an alternative to the systems that use mechanical scanners, encoders, and sophisticated UT machines. It used a camera to record the probe’s movement and a projected laser grid obtained by a laser pattern generator to locate the probe on the inspected surface. In this paper, a novel system is proposed to be applied to flat surfaces, in addition to overcoming the other limitations posed due to the use of the laser projection. The proposed system uses two video cameras, one to monitor the probe’s movement on the inspected surface and the other to capture the corresponding digital readout of the thickness gauge. The acquired images of the probe’s position and thickness gauge readout are processed to plot the measured data in a 2D color-coded map. The system is meant to be simpler and more effective than the previous development.


Author(s):  
Allan Matthews ◽  
Adrian Leyland

Over the past twenty years or so, there have been major steps forward both in the understanding of tribological mechanisms and in the development of new coating and treatment techniques to better “engineer” surfaces to achieve reductions in wear and friction. Particularly in the coatings tribology field, improved techniques and theories which enable us to study and understand the mechanisms occurring at the “nano”, “micro” and “macro” scale have allowed considerable progress to be made in (for example) understanding contact mechanisms and the influence of “third bodies” [1–5]. Over the same period, we have seen the emergence of the discipline which we now call “Surface Engineering”, by which, ideally, a bulk material (the ‘substrate’) and a coating are combined in a way that provides a cost-effective performance enhancement of which neither would be capable without the presence of the other. It is probably fair to say that the emergence and recognition of Surface Engineering as a field in its own right has been driven largely by the availability of “plasma”-based coating and treatment processes, which can provide surface properties which were previously unachievable. In particular, plasma-assisted (PA) physical vapour deposition (PVD) techniques, allowing wear-resistant ceramic thin films such as titanium nitride (TiN) to be deposited on a wide range of industrial tooling, gave a step-change in industrial productivity and manufactured product quality, and caught the attention of engineers due to the remarkable cost savings and performance improvements obtained. Subsequently, so-called 2nd- and 3rd-generation ceramic coatings (with multilayered or nanocomposite structures) have recently been developed [6–9], to further extend tool performance — the objective typically being to increase coating hardness further, or extend hardness capabilities to higher temperatures.


Biostatistics ◽  
2019 ◽  
Author(s):  
Dane R Van Domelen ◽  
Emily M Mitchell ◽  
Neil J Perkins ◽  
Enrique F Schisterman ◽  
Amita K Manatunga ◽  
...  

SUMMARYMeasuring a biomarker in pooled samples from multiple cases or controls can lead to cost-effective estimation of a covariate-adjusted odds ratio, particularly for expensive assays. But pooled measurements may be affected by assay-related measurement error (ME) and/or pooling-related processing error (PE), which can induce bias if ignored. Building on recently developed methods for a normal biomarker subject to additive errors, we present two related estimators for a right-skewed biomarker subject to multiplicative errors: one based on logistic regression and the other based on a Gamma discriminant function model. Applied to a reproductive health dataset with a right-skewed cytokine measured in pools of size 1 and 2, both methods suggest no association with spontaneous abortion. The fitted models indicate little ME but fairly severe PE, the latter of which is much too large to ignore. Simulations mimicking these data with a non-unity odds ratio confirm validity of the estimators and illustrate how PE can detract from pooling-related gains in statistical efficiency. These methods address a key issue associated with the homogeneous pools study design and should facilitate valid odds ratio estimation at a lower cost in a wide range of scenarios.


Author(s):  
Mamou Diallo ◽  
Servé W. M. Kengen ◽  
Ana M. López-Contreras

AbstractThe Clostridium genus harbors compelling organisms for biotechnological production processes; while acetogenic clostridia can fix C1-compounds to produce acetate and ethanol, solventogenic clostridia can utilize a wide range of carbon sources to produce commercially valuable carboxylic acids, alcohols, and ketones by fermentation. Despite their potential, the conversion by these bacteria of carbohydrates or C1 compounds to alcohols is not cost-effective enough to result in economically viable processes. Engineering solventogenic clostridia by impairing sporulation is one of the investigated approaches to improve solvent productivity. Sporulation is a cell differentiation process triggered in bacteria in response to exposure to environmental stressors. The generated spores are metabolically inactive but resistant to harsh conditions (UV, chemicals, heat, oxygen). In Firmicutes, sporulation has been mainly studied in bacilli and pathogenic clostridia, and our knowledge of sporulation in solvent-producing or acetogenic clostridia is limited. Still, sporulation is an integral part of the cellular physiology of clostridia; thus, understanding the regulation of sporulation and its connection to solvent production may give clues to improve the performance of solventogenic clostridia. This review aims to provide an overview of the triggers, characteristics, and regulatory mechanism of sporulation in solventogenic clostridia. Those are further compared to the current knowledge on sporulation in the industrially relevant acetogenic clostridia. Finally, the potential applications of spores for process improvement are discussed.Key Points• The regulatory network governing sporulation initiation varies in solventogenic clostridia.• Media composition and cell density are the main triggers of sporulation.• Spores can be used to improve the fermentation process.


2018 ◽  
Vol 66 (10) ◽  
pp. 1487-1491 ◽  
Author(s):  
Jean B Nachega ◽  
Nadia A Sam-Agudu ◽  
Lynne M Mofenson ◽  
Mauro Schechter ◽  
John W Mellors

Abstract Although significant progress has been made, the latest data from low- and middle-income countries show substantial gaps in reaching the third “90%” (viral suppression) of the UNAIDS 90-90-90 goals, especially among vulnerable and key populations. This article discusses critical gaps and promising, evidence-based solutions. There is no simple and/or single approach to achieve the last 90%. This will require multifaceted, scalable strategies that engage people living with human immunodeficiency virus, motivate long-term treatment adherence, and are community-entrenched and ‑supported, cost-effective, and tailored to a wide range of global communities.


Geophysics ◽  
2014 ◽  
Vol 79 (4) ◽  
pp. T243-T255 ◽  
Author(s):  
James W. D. Hobro ◽  
Chris H. Chapman ◽  
Johan O. A. Robertsson

We present a new method for correcting the amplitudes of arrivals in an acoustic finite-difference simulation for elastic effects. In this method, we selectively compute an estimate of the error incurred when the acoustic wave equation is used to approximate the behavior of the elastic wave equation. This error estimate is used to generate an effective source field in a second acoustic simulation. The result of this second simulation is then applied as a correction to the original acoustic simulation. The overall cost is approximately twice that of an acoustic simulation but substantially less than the cost of an elastic simulation. Because both simulations are acoustic, no S-waves are generated, so dispersed converted waves are avoided. We tested the characteristics of the method on a simple synthetic model designed to simulate propagation through a strong acoustic impedance contrast representative of sedimentary geology. It corrected amplitudes to high accuracy for reflected arrivals over a wide range of incidence angles. We also evaluated results from simulations on more complex models that demonstrated that the method was applicable in realistic sedimentary models containing a wide range of seismic contrasts. However, its accuracy was reduced for wide-angle reflections from very high impedance contrasts such as a shallow top-salt interface. We examined the influence of modeling at coarse grid resolutions, in which converted S-waves in the equivalent elastic simulation are dispersed. These results provide some validation for the accuracy of the method when applied using finite-difference grids designed for acoustic modeling. The method appears to offer a cost-effective means of modeling elastic amplitudes for P-wave arrivals in a useful range of velocity models. It has several potential applications in imaging and inversion.


2020 ◽  
pp. 57-60
Author(s):  
K.I. Mustafaev ◽  
◽  
◽  

The production of residual oil reserves in the fields being in a long-term exploitation is of current interest. The extraction of residual oil in such fields was cost-effective and simple technological process and is always hot topic for researchers. Oil wells become flooded in the course of time. The appearance of water shows in production wells in the field development and operation is basically negative occurrence and requires severe control. Namely for this reason, the studies were oriented, foremost, to the prevention of water shows in production well and the elimination of its complications as well. The paper discusses the ways of reflux efficiency increase during long-term exploitation and at the final stages of development to prevent the irrigation and water use in production wells.


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