Novel Simulator for Design and Analysis of Matrix Acidizing Jobs with Fluoroboric Acid in Sandstone Reservoirs

2021 ◽  
Author(s):  
Mohammed Qamruzzaman ◽  
Mandeep Khan ◽  
Dhirendra Chandra Roy ◽  
Ravi Raman
Keyword(s):  
Reservoir Rock ◽  
Core Flooding ◽  
Pumping Rate ◽  
Matrix Acidizing ◽  
Skin Factor ◽  
Computational Fluid Dynamics Cfd ◽  
Made In ◽  
Do So ◽  
Acid Treatments

Abstract Matrix acidizing with fluoroboric acid (HBF4) has gained special attention as not only it provides deeper penetration of in – situ generated hydrofluoric acid, but also stabilizes formation fines by binding them to the pore surface. While numerous mathematical models exist in literature for design and evaluation of conventional mud acid treatments, fewer attempts have been made in developing a lab validated model that can do so for fluoroboric acid treatments. This paper presents a novel mathematical model that has been developed taking into account the chemical kinetics and equilibrium aspects of important reactions and fluid flow inside the reservoir rock. The solution to the governing equations has been obtained through tools of computational fluid dynamics (CFD). The model has been validated rigorously through use of state-of-the-art core flooding and ion chromatography setups. The resulting simulator can be used to design an optimum fluoroboric acid treatment by analysing the effects of all the important factors including reservoir temperature, formation mineralogy and job execution details like initial acid concentration, pumping rate, job volume and shut-in time post treatment. Simulation results with the developed model indicate that although penetration of fluoroboric acid is much larger compared to mud acid, its overall effect on skin factor is inferior for temperatures less than 90 °C. Stimulation in such wells should be preferred with mud acid which can be followed by fluoroboric acid for fines stabilization. For temperatures more than 120 °C, stimulation effects of fluoroboric acid become comparable to that of mud acid. Under these conditions, it can be used as an alternate fluid to mud acid to prevent issues of secondary and tertiary precipitation. It is found that major stimulation benefits with fluoroboric acid are realized during pumping and subsequent shutting of well, which is a common practice with fluoroboric acid, has relatively smaller effect on skin factor. Apart from design and evaluation of fluoroboric acid treatments, the simulator can also be used for analyzing mud acid and mud acid followed by fluoroboric acid treatments thus enabling the user to select and design the best suited treatment for a given well.

Acidizing Workflow for Optimized Well Performance in Zhdanov and Lam Oil Fields Offshore Caspian Sea

2021 ◽  
Author(s):  
Ruslan Kalabayev ◽  
Ekaterina Sukhova ◽  
Gadam Rovshenov ◽  
Roman Kontarev
Keyword(s):  
Experimental Data ◽  
Caspian Sea ◽  
Laboratory Testing ◽  
Efficiency Calibration ◽  
Oil Fields ◽  
Reservoir Rock ◽  
Rock Matrix ◽  
Acid Rock ◽  
Matrix Acidizing ◽  
Acid Treatments

Abstract Successful sandstone matrix stimulation treatments require addressing complex mineralogy, correctly identifying formation damage, selecting the best stimulation fluids, and placing these fluids correctly. The objective of this paper is to demonstrate a workflow considering laboratory testing, advanced software modeling including acid and diverter fluid efficiency calibration using field experimental data, field execution, and relevant case studies in two oil fields located in the Cheleken block, offshore Caspian Sea. Implementation of the workflow has led to positive results. Matrix acidizing was selected as the primary method for restoring production of the oil wells drilled into sandstone reservoirs due to the reservoir characteristics. Deep Zhdanov wells and shallower Lam wells possess ~15 and ~250 md permeability and ~90 and ~50°C static reservoir temperature, respectively. The target rock mineralogy in both fields predominantly consists of quartz, chlorite, and carbonate minerals. Fluids selection, stimulation design and job execution followed the above mentioned workflow. Treatment modeling considered calibration factors derived from field testing and incorporated several acid and diverter systems. A mix of bullhead and coiled tubing placed treatments were employed. The first step of the workflow considered characterization of the rock mineralogy and selection of the best-fit treatment fluids. Rock dissolution and X-ray diffraction (XRD) tests were run to develop the optimum formulations for the treatment conditions. Further, the results of the laboratory testing were incorporated into the advanced matrix acidizing simulator to model and optimize the treatment schedules. The recently developed matrix stimulation software incorporates geochemical, thermal, and placement simulations calibrated with experimental data. Offset well stimulation treatment pressure match was done by calibrating the acid and diverter fluid efficiency, and those calibrated values were considered for design simulations for the following acid treatments. In this paper, the term "acid efficiency" is defined as a measure of the relative rate at which the acid can penetrate when it flows in the rock matrix as a function of matrix porosity and the overall acid reactivity. The term "diverter efficiency" is defined as a measure of the viscosity developed by a given diverter when it flows in the rock matrix. Such a calibration method accounts for the actual reservoir large-scale acid-rock reaction kinetics. Finally, diagnostic tests and main acid treatments were executed that enabled achieving the desired levels of skin reduction, reservoir placement, zone coverage, and hydrocarbon production rates. Several acid stimulation operations were conducted including three cases in which a low-temperature well with carbonate damage needed repeated acidizing and two additional cases that involved wells with deep, hot, and clay-rich pay zones. Several fluid schedules were applied including foam diversion technique. The above approach uses a unique method of acid efficiency calibration using field experimental data. It requires good knowledge of reservoir rock mineralogy, porosity, and permeability profiles in the zones of interest. Pretreatment skin is calibrated using production data prior to acid efficiency calibration based on matching the actual treatment pressures. The pressure behavior observed during the following treatments closely matched the design pressures confirming applicability of the approach.

Big Questions in Ecology and Evolution

2009 ◽  
Author(s):  
Thomas N. Sherratt ◽  
David M. Wilkinson
Keyword(s):  
Partial Solution ◽  
Fundamental Importance ◽  
Evolutionary Perspective ◽  
Text Book ◽  
Broad Audience ◽  
The Future ◽  
The Tropics ◽  
Made In ◽  
Do So

Why do we age? Why cooperate? Why do so many species engage in sex? Why do the tropics have so many species? When did humans start to affect world climate? This book provides an introduction to a range of fundamental questions that have taxed evolutionary biologists and ecologists for decades. Some of the phenomena discussed are, on first reflection, simply puzzling to understand from an evolutionary perspective, whilst others have direct implications for the future of the planet. All of the questions posed have at least a partial solution, all have seen exciting breakthroughs in recent years, yet many of the explanations continue to be hotly debated. Big Questions in Ecology and Evolution is a curiosity-driven book, written in an accessible way so as to appeal to a broad audience. It is very deliberately not a formal text book, but something designed to transmit the excitement and breadth of the field by discussing a number of major questions in ecology and evolution and how they have been answered. This is a book aimed at informing and inspiring anybody with an interest in ecology and evolution. It reveals to the reader the immense scope of the field, its fundamental importance, and the exciting breakthroughs that have been made in recent years.

scholarly journals Experimental and CFD Simulations of the Aerosol Flow in the Air Ventilating the Underground Excavation in Terms of SARS-CoV-2 Transmission

Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4743
Author(s):  
Tomasz Janoszek ◽  
Zbigniew Lubosik ◽  
Lucjan Świerczek ◽  
Andrzej Walentek ◽  
Jerzy Jaroszewicz
Keyword(s):  
Numerical Calculations ◽  
Mining Institute ◽  
Ventilation Network ◽  
Underground Excavation ◽  
In Situ Tests ◽  
Ansys Fluent ◽  
Aerosol Emission ◽  
Ansys Cfx ◽  
Computational Fluid Dynamics Cfd

The paper presents the results of experimental and model tests of transport of dispersed fluid droplets forming a cloud of aerosol in a stream of air ventilating a selected section of the underground excavation. The excavation selected for testing is part of the ventilation network of the Experimental Mine Barbara of the Central Mining Institute. For given environmental conditions, such as temperature, pressure, relative humidity, and velocity of air, the distribution of aerosol droplet changes in the mixture of air and water vapor along the excavation at a distance was measured at 10 m, 25 m, and 50 m from the source of its emission. The source of aerosol emission in the excavation space was a water nozzle that was located 25 m from the inlet (inlet) of the excavation. The obtained results of in situ tests were related to the results of numerical calculations using computational fluid dynamics (CFD). Numerical calculations were performed using Ansys-Fluent and Ansys-CFX software. The dimensions and geometry of the excavation under investigation are presented. The authors describe the adopted assumptions and conditions for the numerical model and discuss the results of the numerical solution.

Quel corpus pour l’étude du dialecte niçois ?

2021 ◽  
Vol 137 (2) ◽  
pp. 344-361
Author(s):  
Philippe Del Giudice
Keyword(s):  
Middle Ages ◽  
Written Language ◽  
Linguistic Features ◽  
Descriptive Grammar ◽  
Written Production ◽  
Starting Point ◽  
Social Use ◽  
Over Time ◽  
Made In ◽  
Do So

Abstract A new project has just been launched to write a synchronic, descriptive grammar of Niçois, the Occitan dialect of Nice. In this article, I define the corpus of the research. To do so, I first review written production from the Middle Ages to the present. I then analyze the linguistic features of Niçois over time, in order to determine the precise starting point of the current language state. But because of reinforced normativism and the decreasing social use of Niçois among the educated population, written language after WWII became artificial and does not really correspond to recordings made in the field. The corpus will thus be composed of writings from the 1820’s to WWII and recordings from the last few decades.

scholarly journals The 1930s Horror Adventure Film on Location in Jamaica: ‘Jungle Gods’, ‘Voodoo Drums’ and ‘Mumbo Jumbo’ in the ‘Secret Places of Paradise Island’

Humanities ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 62
Author(s):  
Emiel Martens
Keyword(s):  
American Literature ◽  
American Empire ◽  
Sound Film ◽  
Mumbo Jumbo ◽  
First Sound ◽  
African Caribbean ◽  
The Caribbean ◽  
Black Populations ◽  
Made In ◽  
Do So

In this article, I consider the representation of African-Caribbean religions in the early horror adventure film from a postcolonial perspective. I do so by zooming in on Ouanga (1935), Obeah (1935), and Devil’s Daughter (1939), three low-budget horror productions filmed on location in Jamaica during the 1930s (and the only films shot on the island throughout that decade). First, I discuss the emergence of depictions of African-Caribbean religious practices of voodoo and obeah in popular Euro-American literature, and show how the zombie figure entered Euro-American empire cinema in the 1930s as a colonial expression of tropical savagery and jungle terror. Then, combining historical newspaper research with content analyses of these films, I present my exploration into the three low-budget horror films in two parts. The first part contains a discussion of Ouanga, the first sound film ever made in Jamaica and allegedly the first zombie film ever shot on location in the Caribbean. In this early horror adventure, which was made in the final year of the U.S. occupation of Haiti, zombies were portrayed as products of evil supernatural powers to be oppressed by colonial rule. In the second part, I review Obeah and The Devil’s Daughter, two horror adventure movies that merely portrayed African-Caribbean religion as primitive superstition. While Obeah was disturbingly set on a tropical island in the South Seas infested by voodoo practices and native cannibals, The Devil’s Daughter was authorized by the British Board of Censors to show black populations in Jamaica and elsewhere in the colonial world that African-Caribbean religions were both fraudulent and dangerous. Taking into account both the production and content of these movies, I show that these 1930s horror adventure films shot on location in Jamaica were rooted in a long colonial tradition of demonizing and terrorizing African-Caribbean religions—a tradition that lasts until today.

Engaging with the science and politics of biodiversity futures: a literature review

2021 ◽  
pp. 1-8
Author(s):  
Carina Wyborn ◽  
Elena Louder ◽  
Mike Harfoot ◽  
Samantha Hill
Keyword(s):  
Human Life ◽  
Global Environmental Change ◽  
Life Forms ◽  
Trade Offs ◽  
Global Environmental ◽  
Science And Politics ◽  
Science Community ◽  
Impact On Biodiversity ◽  
Made In

Summary Future global environmental change will have a significant impact on biodiversity through the intersecting forces of climate change, urbanization, human population growth, overexploitation, and pollution. This presents a fundamental challenge to conservation approaches, which seek to conserve past or current assemblages of species or ecosystems in situ. This review canvases diverse approaches to biodiversity futures, including social science scholarship on the Anthropocene and futures thinking alongside models and scenarios from the biophysical science community. It argues that charting biodiversity futures requires processes that must include broad sections of academia and the conservation community to ask what desirable futures look like, and for whom. These efforts confront political and philosophical questions about levels of acceptable loss, and how trade-offs can be made in ways that address the injustices in the distribution of costs and benefits across and within human and non-human life forms. As such, this review proposes that charting biodiversity futures is inherently normative and political. Drawing on diverse scholarship united under a banner of ‘futures thinking’ this review presents an array of methods, approaches and concepts that provide a foundation from which to consider research and decision-making that enables action in the context of contested and uncertain biodiversity futures.

Some Palaeoliths from South Arabia

1954 ◽  
Vol 19 (2) ◽  
pp. 189-218 ◽  
Author(s):  
G. Caton-Thompson
Keyword(s):  
Geographical Society ◽  
South Arabia ◽  
First Time ◽  
Do So

The material here described was found in the Hadhramaut by Elinor Gardner and myself between November 1937 and March 1938. My personal investigation of the Palaeolithic Age was limited by pre-Islamic excavations, and I am therefore indebted to her for the gathering of most of the specimens in situ in terrace gravels, and to her detailed study of their positions.The collection consists mainly of groups from four fairly widely separated localities; the physiography of these has already been outlined in a comprehensive paper published in the Geographical Journal. Whenever appropriate to the purpose of this account, which is to place for the first time on illustrated record all we observed about the palaeoliths, I have reused in this different context illustrations of Quaternary environment which appeared in that Journal. With thanks I acknowledge the permission of the Royal Geographical Society to do so.

Measuring Reservoir Compaction Through Radioactive Marker Technique

2002 ◽  
Vol 124 (4) ◽  
pp. 269-275
Author(s):  
Paolo Macini ◽  
Ezio Mesini
Keyword(s):  
Land Subsidence ◽  
Reservoir Rock ◽  
Reservoir Compaction ◽  
Critical Comparison ◽  
In Situ Method ◽  
Sufficient Precision ◽  
Good Agreement

Radioactive Marker Technique (RMT), an in-situ method to measure reservoir rock compaction and to evaluate uniaxial compressibility coefficients Cm, is examined here. Recent field applications seems to confirm that RMT-derived Cm’s match with sufficient precision with those calculated from land subsidence observed over the field by means of geodetic surveys, but are not always in good agreement with those derived from lab measurements. In particular, here is reported an application of RMT in the Italian Adriatic offshore, which highlights the discrepancies of Cm’s measurements from lab and RMT. At present, these discrepancies aren’t thoroughly understood, so, from an applicative standpoint, it is still necessary to perform a critical comparison and integration between both set of data.

In situ hybridization to lampbrush chromosomes: a potential source of error exposed

1980 ◽  
Vol 41 (1) ◽  
pp. 115-123
Author(s):  
H.G. Callan ◽  
R.W. Old
Keyword(s):  
Lampbrush Chromosome ◽  
Single Pair ◽  
Lampbrush Chromosomes ◽  
Triturus Cristatus ◽  
Rna Transcripts ◽  
Potential Source ◽  
Source Of Error ◽  
Simple Sequence ◽  
Do So

Denatured 3H-labelled DNAs containing Xenopus or human globin sequences hybridize to RNA transcripts on a single pair of lateral loops on lampbrush chromosome IX of Triturus cristatus carnifex, and to no other loops on this chromosome or the rest of the complement. However they do so, not because of the globin sequences in the probes, but rather because the plasmids from which the probes were prepared were constructed with G.C homopolymer tails. Simple sequence poly d(C/G)n probes also hybridize with RNA transcripts on this same pair of loops, and with no others.

Enhanced Oil Recovery Application of Nanoparticles in Niger Delta Water-Wet Reservoir Rock

2021 ◽  
Author(s):  
Tinuola Udoh
Keyword(s):  
Enhanced Oil Recovery ◽  
Oil Recovery ◽  
Niger Delta ◽  
Oil Production ◽  
Reservoir Rock ◽  
Core Flooding ◽  
Core Samples ◽  
Recovery Potential ◽  
Secondary Formation ◽  
Injection Modes

Abstract In this paper, the enhanced oil recovery potential of the application of nanoparticles in Niger Delta water-wet reservoir rock was investigated. Core flooding experiments were conducted on the sandstone core samples at 25 °C with the applications of nanoparticles in secondary and tertiary injection modes. The oil production during flooding was used to evaluate the enhanced oil recovery potential of the nanoparticles in the reservoir rock. The results of the study showed that the application of nanoparticles in tertiary mode after the secondary formation brine flooding increased oil production by 16.19% OIIP. Also, a comparison between the oil recoveries from secondary formation brine and nanoparticles flooding showed that higher oil recovery of 81% OIIP was made with secondary nanoparticles flooding against 57% OIIP made with formation brine flooding. Finally, better oil recovery of 7.67% OIIP was achieved with secondary application of nanoparticles relative to the tertiary application of formation brine and nanoparticles flooding. The results of this study are significant for the design of the application of nanoparticles in Niger Delta reservoirs.

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