Permeability determination of the medium according to the analysis of laboratory hydraulic fracturing curves.

2021 ◽  
Author(s):  
Helen Novikova ◽  
Mariia Trimonova
Keyword(s):  
Data Analysis ◽  
Hydraulic Fracturing ◽  
Laboratory Experiments ◽  
Similarity Criteria ◽  
Real Field ◽  
Experimental Setup ◽  
Time Period ◽  
Fracture Closure ◽  
Fracturing Process

<p>Recently, attention to the development of low-permeable reservoirs has been increasing. More and more attention is being paid to the search for various methods of data analysis of mini-hydraulic fracturing and computer modeling of the hydraulic fracturing process, which will simplify the entire procedure of hydraulic fracturing in a real field and reduce financial costs. The increase in interest is due to the fact that the results of the hydraulic fracturing are used to determine some important characteristics of the formation.</p><p>One of such important characteristics of a reservoir is permeability. In the course of this study, the data obtained from a series of laboratory experiments on mini-hydraulic fracturing were processed. The main goal was to determine the value of permeability of the medium in which the hydraulic fracture was formed and propagated, with the help of various standard methods. The second objective of the study was to compare the calculated values with real ones known from preliminary conducted laboratory experiments.</p><p>In the frame of the work, the laboratory experiments on mini-hydraulic fracturing were carried out using a special experimental setup [1]. The uniqueness of this experimental setup lies in the fact that it allows to perform a triaxial loading of the sample under consideration. The sample material was selected according to the similarity criteria between the fracturing process in the experiment and the fracturing process in the real field. These features make it possible to approximate the conditions of a laboratory experiment on hydraulic fracturing to real field conditions.</p><p>As a result, pressure-time dependencies were obtained for series of laboratory experiments. Further analysis of the curves was carried out in the time period after fracture closure.</p><p>In the course of data analysis, the flow regimes in the medium during the time period after fracture closure were estimated. After that, the values of permeability were calculated using approach introduced by Nolte [2, 3]. The permeability values were also estimated using the method proposed by Horner [4] and later modified by Nolte [5]. All theoretically obtained values were compared with real values of permeabilities.</p><p><strong>Acknowledgements</strong></p><p>The reported study was funded by RFBR, project number 20-35-80018, and state task 0146-2019-0007.</p><p><strong>References</strong></p><p>1. Trimonova M., Baryshnikov N., Zenchenko E., Zenchenko P., Turuntaev S.: “The Study of the Unstable Fracture Propagation in the Injection Well: Numerical and Laboratory Modelling,” (2017).</p><p>2. Nolte, K. G.: “Determination of Fracture Parameters from Fracturing Pressure Decline,” Las Vegas (1979).</p><p>3. Nolte, K. G.: “A General Analysis of Fracturing Pressure Decline With Application to Three Models,” (1986).</p><p>4. Horner, D. R.: “Pressure Build-Up in Wells,” Netherlands (1951).</p><p>5. Nolte, K. G., Maniere, J. L., Owens, K. A.: “After-Closure Analysis of Fracture Calibration Tests,” Texas (1997).</p>

Simulation of Hydraulic Fracturing Processes

1980 ◽  
Vol 20 (06) ◽  
pp. 487-500 ◽  
Author(s):  
A. Settari
Keyword(s):  
Heat Transfer ◽  
Fluid Flow ◽  
Hydraulic Fracturing ◽  
Fracture Propagation ◽  
Thermal Recovery ◽  
Reservoir Rock ◽  
Flow And Heat Transfer ◽  
Fracture Closure ◽  
Fracturing Process

Abstract A mathematical model of the fracturing process, coupling the fracture mechanics and fracture propagation with reservoir flow and heat transfer, has been formulated. The model is applicable to fracturing treatments as well as to high leakoff applications such as fractured waterfloods and thermal fractures. The numerical technique developed is capable of simulating fracture extension for reasonably coarse grids, with truncation error being minimized for high leakoff applications when the grid next to the fracture is approximately square. With the aid of the model, a generalization of Carter's propagation formula has been developed that is also valid for high fluid-loss conditions. The capabilities of the model are illustrated by examples of heat transfer and massive-hydraulic-fracturing (MHF) treatment calculation. Introduction Induced fracturing of reservoir rock occurs under many different circumstances. Controlled hydraulic fracturing is an established method for increasing productivity of wells in low-permeability reservoirs. The technology of fracturing and the earlier design methods are reviewed by Howard and Fast.1 In waterflooding, injection pressures also often exceed fracturing pressures. This may result from poor operational practices, but it also could be intended to increase injectivity.2 In heavy oils, such as Alberta oil sands, most in-situ thermal recovery techniques rely on creating injectivity by fracturing the formation with steam.3 Fracturing also is being used as a method for deterining in-situ stresses4 and for establishing communication between wells for extraction of geothermal energy.5,6 Finally, fractures may be produced by explosive treatment or induced thermal stresses (such as in radioactive waste disposal). To date, most of the research has been directed toward the understanding and design of fracture stimulation treatments, with emphasis on predicting fracture geometry.7–11 The influence of fluid flow and heat transfer in the reservoir has been neglected or accounted for by various approximations in these methods. On the other hand, the need for reservoir engineering analysis of fractured wells led to the development of analytical techniques and numerical models for predicting postfracture performance.1 A common feature of all these methods is that they treat only stationary fractures, which therefore must be computed using some of the methods of the first category mentioned earlier. With the high costs associated with MHF,17–19 and with increasing complexity of the treatments, it is becoming important to be able to understand the interaction of the physical mechanisms involved and to improve the designs. This paper presents a numerical model of the fracturing process that simultaneously accounts for the rock mechanics, two-phase fluid flow, and heat transfer, both in the fracture and in the reservoir. The model is capable of predicting fracture propagation, fluid leakoff and heat transfer, fracture closure, cleanup, and postfracture performance. Although the detailed calculations of geometry, proppant transport, etc., have not been included, they can be integrated in a natural way within the present model. Because vertical fractures are prevalent except for very shallow depths, the discussion is limited to vertical fracturing. The paper focuses attention on the formulation of the basic model and the numerical techniques in general. Applications to fracturing treatments and the specific enhancements of the model are described in a more recent paper.20

scholarly journals Multiphase Multicomponent Numerical Modeling for Hydraulic Fracturing with N-Heptane for Efficient Stimulation in a Tight Gas Reservoir of Germany

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3111
Author(s):  
Faisal Mehmood ◽  
Michael Z. Hou ◽  
Jianxing Liao ◽  
Muhammad Haris ◽  
Cheng Cao ◽  
...  
Keyword(s):  
Hydraulic Fracturing ◽  
Gas Production ◽  
Real Field ◽  
Fluid Viscosity ◽  
Tight Gas ◽  
Gas Reservoir ◽  
Hydraulic Stimulation ◽  
Fracture Closure ◽  
Tight Gas Reservoir ◽  
Water Based

Conventionally, high-pressure water-based fluids have been injected for hydraulic stimulation of unconventional petroleum resources such as tight gas reservoirs. Apart from improving productivity, water-based frac-fluids have caused environmental and technical issues. As a result, much of the interest has shifted towards alternative frac-fluids. In this regard, n-heptane, as an alternative frac-fluid, is proposed. It necessitates the development of a multi-phase and multi-component (MM) numerical simulator for hydraulic fracturing. Therefore fracture, MM fluid flow, and proppant transport models are implemented in a thermo-hydro-mechanical (THM) coupled FLAC3D-TMVOCMP framework. After verification, the model is applied to a real field case study for optimization of wellbore x in a tight gas reservoir using n-heptane as the frac-fluid. Sensitivity analysis is carried out to investigate the effect of important parameters, such as fluid viscosity, injection rate, reservoir permeability etc., on fracture geometry with the proposed fluid. The quicker fracture closure and flowback of n-heptane compared to water-based fluid is advantageous for better proppant placement, especially in the upper half of the fracture and the early start of natural gas production in tight reservoirs. Finally, fracture designs with a minimum dimensionless conductivity of 30 are proposed.

A fast methodology to determine the characteristics of thousands of grains using three-dimensional X-ray diffraction. I. Overlapping diffraction peaks and parameters of the experimental setup

2012 ◽  
Vol 45 (4) ◽  
pp. 693-704 ◽  
Author(s):  
Hemant Sharma ◽  
Richard M. Huizenga ◽  
S. Erik Offerman
Keyword(s):  
Data Analysis ◽  
Three Dimensional ◽  
Experimental Setup ◽  
Centre Of Mass ◽  
X Ray Diffraction ◽  
X Ray ◽  
Overlapping Peaks ◽  
Diffraction Peaks ◽  
Mass Position

A data-analysis methodology is presented for the characterization of three-dimensional microstructures of polycrystalline materials from data acquired using three-dimensional X-ray diffraction (3DXRD). The method is developed for 3DXRD microscopy using a far-field detector and yields information about the centre-of-mass position, crystallographic orientation, volume and strain state for thousands of grains. This first part deals with pre-processing of the diffraction data for input into the algorithms presented in the second part [Sharma, Huizenga & Offerman (2012).J. Appl. Cryst.45, 705–718] for determination of the grain characteristics. An algorithm is presented for accurate identification of overlapping diffraction peaks from X-ray diffraction images, which has been an issue limiting the accuracy of experiments of this type. The algorithm works in two stages, namely the identification of overlapping peaks using a seeded watershed algorithm, and then the fitting of the peaks with a pseudo-Voigt shape function to yield an accurate centre-of-mass position and integrated intensity for the peaks. Regions consisting of up to six overlapping peaks can be successfully fitted. Two simulations and an experiment are used to verify the results of the algorithms. An example of the processing of diffraction images acquired in a 3DXRD experiment with a sample consisting of more than 1600 grains is shown. Furthermore, a procedure for the determination of the parameters of the experimental setup (global parameters) without the need for a calibration sample is presented and validated using simulations. This is immensely beneficial for simplifying experiments and the subsequent data analysis.

ANALISIS NILAI KOHESI DAN KOHERENSIDALAM TERJEMAHAN AL-QUR’AN SURAH AL AL ZALZALAH

2016 ◽  
Vol 1 (2) ◽  
pp. 23
Author(s):  
MUNIRAH MUNIRAH ◽  
HUSAIN SYARIFUDDIN
Keyword(s):  
Data Analysis ◽  
Data Collection ◽  
Data Classification ◽  
Research Data ◽  
Relative Pronoun ◽  
Second Person ◽  
Record Keeping ◽  
Descriptive Research ◽  
Qualitative Descriptive

This study aimed to describe the value of cohesion and coherence contained in the translation of the Qur'an surah Al Zalzalah. This study was a qualitative descriptive research, research data collection techniques using three techniques namely, inventory, rading and understanding, and record keeping. The data analysis used the coding of data, classification data, and the determination of the data. The results showed that the cohesion markers used in the translation of surah Al Zalzalah discourse are: 1) reference, 2) pronouns, ie pronouns second person, and third, the relative pronoun, the pronoun pointer, pen pronouns and pronouns owner, 3 ) conjunctions, namely temporal conjunctions, coordinating conjunctions, subordinating conjunctions, and conjunctions koorelatif, and 4) a causal ellipsis. It mean that there was a coherence in the translation of surah Al Zalzalah discourse are: the addition or addition, pronouns, repetition or repetition, match words or synonyms, in whole or in part, a comparison or ratio of conclusions or results. Keywords: Cohesion, Coherence, sura Al Zalzalah AbstrakPenelitian ini bertujuan untuk mendeskripsikan nilai kohesi dan koherensi yang terdapat dalam terjemahan Al-Qur’an surah Al Zalzalah. Jenis penelitian ini termasuk jenis penelitian deskriptif kualitatif, Teknik pengumpulan data penelitian menggunakan tiga teknik yakni, inventarisasi, baca simak, dan pencatatan. Teknik analisis data menggunakan pengodean data, pengklasifikasian data, dan penentuan data. Hasil penelitian menunjukkan bahwa pemarkah kohesi yang digunakan dalam wacana terjemahan surah Al Zalzalah adalah: 1) referensi, 2) pronomina, yaitu kata ganti orang kedua, dan ketiga, kata ganti penghubung, kata ganti penunjuk, kata ganti penanya dan kata ganti empunya, 3) konjungsi, yaitu konjungsi temporal, konjungsi koordinatif, konjungsi subordinatif, dan konjungsi koorelatif, dan 4) elipsis kausal. Sarana koherensi yang terdapat di dalam wacana terjemahan surah Al Zalzalah adalah: penambahan atau adisi, pronomina, pengulangan atau repetisi, padan kata atau sinonim, keseluruhan atau bagian, komparasi atau perbandingan simpulan atau hasil.Kata Kunci: Kohesi, Koherensi, surah Al Zalzalah

PENENTUAN KRITERIA PENILAIAN KESAN JUMLAH LEUKOSIT PADA PEMERIKSAAN APUSAN DARAH TEPI

2018 ◽  
Vol 3 (2) ◽  
pp. 52-61
Author(s):  
Dzikra Arwie ◽  
Islawati
Keyword(s):  
Data Analysis ◽  
Statistical Analysis ◽  
Blood Cells ◽  
Blood Smear ◽  
White Blood Cells ◽  
Peripheral Blood Smear ◽  
Field Of View ◽  
Laboratory Observation ◽  
Number Of Cells

Leukocytes or white blood cells have a characteristic characteristic of different cells. Determination of the impression of the number of leukocytes is determined in the number of cells in the field of view. While the number of viewable field cells expressed is still quite varied. The purpose of this study was to determine the number of leukocytes in the field of view and expressed the impression of a sufficient amount. This research was conducted at the Laboratory of Health Analyst Department Panrita Husada Bulukumba on 9 April 2017 to 14 July 2017. This type of research is a laboratory observation that aims to determine the criteria for assessing the impression of the number of leukocytes on a peripheral blood smear. Data analysis using statistical analysis is the average and standard deviations to determine the impression of the number of leukocytes and use 3 inspection zones. The results of this study obtained results in zone IV the number of leukocyte impressions said to be sufficient was 7-10, in zone V the number of leukocyte impressions said to be sufficient was 4-9, and in zone VI the number of leukocyte impressions said to be sufficient was 3-8.  

The relationship between musty-odor-causing organisms and water quality in Lake Biwa

1995 ◽  
Vol 31 (11) ◽  
pp. 153-158 ◽  
Author(s):  
M. Kajino ◽  
K. Sakamoto
Keyword(s):  
Water Quality ◽  
Data Analysis ◽  
Green Algae ◽  
Analytical Methods ◽  
Lake Biwa ◽  
Blue Green Algae ◽  
Odor Compounds ◽  
Musty Odor ◽  
The Relationship

Musty odor has occurred annually in Lake Biwa since 1969. Osaka municipal waterworks, which is located downstream of Lake Biwa, has made many efforts to treat musty-odor compounds produced in Lake Biwa from spring through autumn. With the development of analytical methods for the determination of musty-odor compounds, we have been able to confirm that planktonic blue-green algae are the major causes of the musty-odor occurrences. The relationship between the growth of blue-green algae and the water quality was not so apparent. However, through our data analysis focusing on the relationship between musty-odor occurrences due to Phormidium tenue or Oscillatoria tenuis and some nutrients in Lake Biwa, we found that the concentration of nitrate in water may be an important parameter for the estimation of growth of the algae and the musty-odor behavior.

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