bluuebunny/crossref_metadata_2025_split huggingface dataset:
Experimental Investigation of Two-Phase Flow Properties of Heterogeneous Rocks for Advanced Formation Evaluation
Authors: Aérens Pierre , Torres-Verdín Carlos , Espinoza D. Nicolas 
Published: September 2021

Abstract
An uncommon facet of Formation Evaluation is the assessment of flow-related in situ properties of rocks. Most of the models used to describe two-phase flow properties of porous rocks assume homogeneous and/or isotropic media, which is hardly the case with actual reservoir rocks, regardless of scale; carbonates and grain-laminated sandstones are but two common examples of this situation. The degree of spatial complexity of rocks and its effect on the mobility of hydrocarbons are of paramount importance for the description of multiphase fluid flow in most contemporary reservoirs. There is thus a need for experimental and numerical methods that integrate all salient details about fluid-fluid and rock-fluid interactions. Such hybrid, laboratory-simulation projects are necessary to develop realistic models of fractional flow, i.e., saturation-dependent capillary pressure and relative permeability.
We document a new high-resolution visualization technique that provides experimental insight to quantify fluid saturation patterns in heterogeneous rocks and allows for the evaluation of effective two-phase flow properties. The experimental apparatus consists of an X-ray microfocus scanner and an automated syringe pump. Rather than using traditional cylindrical cores, thin rectangular rock samples are examined, their thickness being one order of magnitude smaller than the remaining two dimensions. During the experiment, the core is scanned quasi-continuously while the fluids are being injected, allowing for time-lapse visualization of the flood front. Numerical simulations are then conducted to match the experimental data and quantify effective saturation-dependent relative permeability and capillary pressure.
Experimental results indicate that flow patterns and in situ saturations are highly dependent on the nature of the heterogeneity and bedding-plane orientation during both imbibition and drainage cycles. In homogeneous rocks, fluid displacement is piston-like, as predicted by the Buckley-Leverett theory of fractional flow. Assessment of capillary pressure and relative permeability is performed by examining the time-lapse water saturation profiles. In spatially complex rocks, high-resolution time-lapse images reveal preferential flow paths along high permeability sections and a lowered sweep efficiency.
Our experimental procedure emphasizes that capillary pressure and transmissibility differences play an important role in fluid-saturation distribution and sweep efficiency at late times. The method is fast and reliable to assess mixing laws for fluid-transport properties of rocks in spatially complex formations.
Boosting Production in the Llanos Orientales Colombia Basin, with an Approach to the Usage of the Completion Fluid. A Recent Case Study
Authors: Diaz Lozano Carlos Mario , Cortes Daza Carlos Andres , Pacheco Gomez Erika Andrea , Plata Ruiz Elizabeth , Castellanos Carvajal Jaime 
Published: September 2021

Abstract
This arcticle highlights the importance of a systematic step change approach to the formulation of completion fluids in the Llanos Basin (LLAB), Colombia, when formation-freshwater is to be used as control - completion (C&C) fluid. The results demonstrate that the process used reduced the formation damage statistics from 41% of the wells drilled to only 16%, boosting production and establishing a best practice for future drilling and completion (D&C) campaigns in the region.
An initial sample of 19 wells was considered to evaluate the damage caused by using formation-freshwater as C&C fluid. Formation-freshwater was selected only considering the fluid density (wellbore pressure), ignoring the negative effects it can have on formation damage. 41% of the wells were damaged, as evidenced by pressure build up. Some of the main damages on the pay-zone in an oil well are due to emulsion blocking, change in wettability, swelling and migration of clays, incompatibility of fluids, and scale formation. A detailed design of completion fluids has a positive influence over well productivity by mitigating formation damage before starting the production stage. The methodology used was aimed at designing the C&C fluid through a step-by-step approach, consisting of: 1) Laboratory tests supported with mineralogical data and oil and formation water properties and 2) Physical-chemical analysis of reservoir fluids and water for mixing purposes. The process involved testing different formulations and then their implementation in the field. The initial tests were conducted in a total of 5 wells in 4 fields. Changes were identified in the formulation to achieve optimal fluid design for each field and then the selected fluid was extended to a total of 24 wells. This was the first time a thoroughly designed completion fluid was used in the region.
The results point towards the need to include surfactants, mutual solvents, and brines to substantially reduce formation damage. The application of new completion fluids enabled the operational teams to optimize the process by steps. The implementation of customized completion fluid reduced the formation damage as evidenced through productivity analyses and pressure build up tests. Only 16% of the wells presented formation damage.
The process applied to reduce formation damage of the Llanos Basin led to a systematic approach for the analysis stage, which may be applied in other areas, where the utilization of formation-freshwater is an issue. The particularly short time frames and best practices derived from the learning curve of this case are worth to be shared with other operators.
Exploiting Natural Nonconservative Geochemical Data to Obtain Reservoir Information
Authors: Wang Yanqing , Liu Zhe , Zhang Yuchen , Lu Jun 
Published: September 2021

Abstract
Geochemical data in produced water contain important reservoir information but are seldomly exploited, especially for the nonconservative chemicals. Some conservative chemical data have been integrated in history matching workflow to obtain better knowledge of reservoirs. However, assuming reservoir chemicals being conservative is impractical because most chemicals are involved in interactions with other chemicals or reservoir rock, and mistakenly regarding nonconservative chemicals as being conservative can cause large error. Nevertheless, once the interactions can be accurately described, nonconservative chemical data can be used to obtain more reservoir information. In this work, a new physicochemical model is proposed to describe the transport of natural nonconservative chemicals (barium and sulfate) in porous media. Both physical reactions, such as ion adsorption and desorption, and chemical reactions, such as barite deposition, are integrated. Based on the new model, the ensemble smoother with multiple data assimilations (ES-MDA) method is employed to update reservoir model parameters by assimilating oil production rate, water production rate, and chemical data (barium and sulfate concentration). Data assimilation results show that integrating geochemical data in ES-MDA algorithm yields additional improvements in estimation of permeability. Besides, clay content distribution, which is critical in injection water breakthrough percentage calculation, can be accurately estimated with relative root mean square error (rRMSE) being as small as 0.1. However, mistakenly regarding nonconservative chemicals as conservative can cause large errors in reservoir parameters estimation. Accurately modeling the chemical interactions is crucial for integrating chemical data in history matching algorithm.
Asset of the Future - Comprehensive Business Transformation Program
Authors: Sitnikov Alexander , Doktor Sergei , Margarit Andrei 
Published: September 2021

Abstract
In the recent years the oil and gas industry has started facing an unprecedented number of challenges. The average return on capital in the industry has deteriorated which results in investor mistrust and costs being higher than ever. Debt capital became two times costlier than for alterative types of energy. More conventional oilfields become depleted and new reserves are usually quite complex to develop. These and other challenges such as intense competition between oil and gas companies, the energy transition agenda as well as the volatility of oil prices in the aftermath of the pandemic are pushing the O&G companies to transform themselves.
Gazprom Neft introduced the "Asset of the Future" program in late 2018 as a timely response which was aimed at completely transforming the Upstream business model. The main issue with the transformation was the scale of it, which included 10 subsidiaries (or subs) and more than 200 different processes. In this case traditional approaches such as improving each operation one by one would not suffice as the company sought a rapid and highly efficient implementation of changes. As such the program had to develop a new approach that focused on the integration of all business parts and continuous improvement. Integration of people, technology and processes will lead to better collaboration and as a result - to smarter decisions and better execution.
Pretreatment of Produced Waters Containing High Total Dissolved Solids
Authors: Kaishentayev Damir , Hascakir Berna 
Published: September 2021

Abstract
There are mainly two types of solids in the oil field waters; Suspended Solids (SS) and Total Dissolved Solids (TDS). While it is easy to remove SS from water, removal of TDS requires the application of advance filtration techniques such as reverse osmosis or ultra-filtration. Because these techniques cannot handle high volumes of the oilfield waters with high TDS content, produced waters originated from hydraulic fracturing activities cannot be treated by using these advance technologies. Thus, in this study we concentrated on the pretreatment of these waters.
We investigated the feasibility of the Coagulation, Flocculation, and Sedimentation (CFS) process as pretreatment method to reduce mainly SS in Produced Water (PW) samples. We collected samples from 14 different wells in the Permian Basin. First, we characterized the water samples in terms of pH, SS, TDS, Zeta potential (ZP), Turbidity, Organic matter presence and different Ion concentration. We tested varying doses of several organic and inorganic chemicals, and on treated water samples we measured pH, TDS, SS, Turbidity, ZP and Ions. Then, we compared obtained results with the initial PW characterizations to determine the best performing chemicals and their optimal dosage (OD) to remove contaminants effectively.
The cation and anion analyses on the initial water samples showed that TDS is mainly caused by the dissolved sodium and chlorine ions. ZP results indicated that SS are mainly negatively charged particles with absolute values around 20 mV on average. Among the tested coagulants, the best SS reduction was achieved through the addition of ferric sulfate, which helped to reduce the SS around 86%. To further lessen SS, we tested several organic flocculants in which the reduction was improved slightly more.
We concluded while high TDS in the Permian basin does not implement a substantial risk for the reduction of fracture conductivity, SS is posing a high risk. Our study showed, depending on components of the initial PW, reuse of the pretreated water for fracturing may minimize fracture conductivity damage.
Chelating Agents as a Stimulation Fluid with a Negative Reaction Order: More Diluted Solutions React Faster with Carbonates
Authors: Ivanishin Igor , Samouei Hamidreza 
Published: September 2021

Abstract
Chelating agents are used to stimulate high-temperature carbonate reservoirs and remove mineral scales. For field applications, commercial chelates—EDTA, DTPA, GLDA, etc.—are commonly supplied as 35–50 wt% (1.2–1.7 M) solutions and diluted two times in water. However, the dependence of the reaction rate on the concentration of chelate in solution has never been quantified. This paper focuses on determining the kinetics of calcite dissolution as a function of the dilution factor of commonly used chelates at acidic pH. Using a rotating disk apparatus, the kinetics of calcite marble dissolution in 0.1–0.25 M EDTA (pH=4.9–5.0), 0.1–0.25 M DTPA (pH=3.5–5.0), and 0.28–0.85 M GLDA (pH=3.7–5.0) solutions has been investigated. The dissolution of calcite in all chelates has a negative fractional-order that increases with temperature in the range -0.6 &lt; n &lt; -1.9. Thus, less concentrated chelate solutions react faster with calcite, and the effect of chelate dilution becomes less pronounced with a temperature increase. For example, three times dilution of pH≈3.7 commercial GLDA solution—from commonly used 50 vol% (0.85 M) to 16.7 vol% (0.28 M)—increases calcite dissolution rate 8.4, 4.9, 2.7, and 2.0 times at 98.6, 116.6, 134.6, and 188.6°F, respectively. Dilution of pH=5.0 EDTA and pH=3.5 DTPA from 0.25 M to 0.1 M increases the dissolution rate of calcite 1.4–3.1 times at 98.6–188.6°F. Probable reasons for such an unusual reaction behavior are discussed in the paper. Presented results are integral for designing the stimulation operations in carbonate reservoir rocks and the removal of carbonate scales.
Investment Strategy of CO2-EOR in China: Analysis Based on Real Option Approach
Authors: Bi Jianfei , Li Jing , Chen Zhangxin John , Gao Yanling , Liu Yishan , Wu Keliu , Dong Xiaohu , Feng Dong , Zhang Shengting 
Published: September 2021

Abstract
As the most potential Carbon Capture, Utilization, and Storage (CCUS) technology, CO2-enhanced oil recovery (CO2-EOR) can both improve oil recovery and relieve the pressure of reducing CO2 emission. However, CO2-EOR projects have not been substantially deployed in China due to the significant investment and high uncertainties of technology, market, and policy. Therefore, identifying potential bottlenecks, and developing effective investment strategies are of great necessity at present. In this work, a real option approach combined with reservoir simulation technologies is proposed, which can investigate the optimal deployment timing and the investment value of the CO2-EOR projects. Meanwhile, a sensitivity analysis is conducted to examine the effects of different uncertainties. The results show that real option approach is suitable for the evaluation of CO2-EOR projects because it can fully take the flexibility of investment time into account. And it is found that under the current investment environment, it is difficult for China to deploy CO2-EOR projects on a large scale before 2030. High oil prices, low CO2 purchase prices, and transportation of CO2 by pipeline can bring forward the investment time and increase the investment value. Besides, government subsidies and technological progress are also favorable for the deployment of the project. Compared with technological progress, the effect of subsidies is more obvious, while it should be noted that huge subsidies will bring a financial burden to the government. In a word to launch CO2-EOR projects earlier and make it play a more important role in China's carbon emission reduction, a compound strategy should be made based on consideration of all these influencing factors.
Steady-State Liquid Permeability Measurements in Samples from the Bakken Formation, Williston Basin, USA
Authors: Ramiro-Ramirez Sebastian , Flemings Peter B. , Bhandari Athma R. , Jimba Oluwafemi Solomon 
Published: September 2021

Abstract
We measured steady-state liquid (dodecane) permeability in four horizontal core plugs from the middle member of the Bakken Formation at multiple effective stress conditions to investigate how permeability evolves with confining stress and to infer the matrix permeability. Three of the four tested samples behaved almost perfectly elastically as the hysteresis effect was negligible. In contrast, the fourth sample showed a permeability decrease of ~40% at the end of the test program. Our interpretation is that the closure of open artificial micro-fractures initially present in the sample (based on micro-CT imaging) caused that permeability hysteresis. The matrix permeability to dodecane (oil) of the tested samples is between ~50 nD and ~520 nD at the confining pressure of 9500 psi. The 520 nD sample exhibited the lowest porosity, the highest calcite content, and the largest dominant pore throat radii. In contrast, the 50 nD sample was more porous, and exhibited the highest dolomite content and the smallest dominant pore throat radii. This study shows that our multi-stress testing protocol allows the study of the permeability hysteresis effect to interpret the matrix permeability. We also document the presence of middle Bakken lithologies with permeabilities up to one order of magnitude greater than others. These permeable lithologies may have a significant contribution to well production rates.
Reconstruction and Synthesis of Source Rock Images at the Pore Scale
Authors: Anderson Timothy 
Published: September 2021

Abstract
Image-based characterization of rock fabric is critical for understanding recovery mechanisms in shale formations due to the significant multiscale nature of shale source rocks. Nanoscale imaging is particularly important for characterizing pore-scale structure of shales. Nanoimaging techniques, however, have a tradeoff between high-resolution/high-contrast sample-destructive imaging modalities and low-contrast/low-resolution sample-preserving modalities. Furthermore, acquisition of nanoscale images is often time-consuming, expensive, and requires signficant levels of expertise, resulting in small image datasets that do not allow for accurate quantification of petrophysical or morphological properties. In this work, we introduce methods for overcoming these challenges in image-based characterization of the fabric of shale source rocks using deep learning models. We present a multimodal/multiscale imaging and characterization workflow for enhancing non-destructive microscopy images of shale. We develop training methods for predicting 3D image volumes from 2D training data and simulate flow through the predicted shale volumes. We then present a novel method for synthesizing porous media images using generative flow models. We apply this method to several datasets, including grayscale and multimodal 3D image volume generation from 2D training images. Results from this work show that the proposed image reconstruction and generation approaches produce realistic pore-scale 3D volumes of shale source rocks even when only 2D image data is available. The models proposed here enable new capabilities for non-destructive imaging of source rocks and we hope will improve our ability to characterize pore-scale properties and phenomena in shales using image data.
Comparative two-dimensional fluorescence gel electrophoresis
Authors: König Simone , Ackermann Doreen 
Published: September 2021

Abstract
Comparative two-dimensional gel electrophoresis (CoFGE) is a special version of two-dimensional polyacrylamide GE (2D-PAGE) and related to difference GE (2D-DIGE). It provides reproducibility and standardisation for 2D-PAGE by introducing a reference to the experiment. CoFGE uses different fluorescent labels to distinguish analyte and a marker protein mixture. The method allows in silico correction of the assignment of gel-separated proteins based on the co-run references, which form a grid of landmarks across the entire gel. The variability of spot coordinates is reduced to ~1% error and data can thus be compared to results generated independently with the same method. In this way, searchable repositories of gel-separated proteins become feasible. In addition, the CoFGE experimental principle can be used for protein quantification by applying the proteins of the marker grid in different concentrations. Here we present the protocol for conducting a CoFGE experiment, which takes about 2 days to complete for a technician skilled in GE.
Autoimmune myelofibrosis associated with autoimmune hemolytic anemia successfully treated with ruxolitinib
Authors: Sato Shuku , Kamata Wataru , Tamai Yotaro 
Published: September 2021

Abstract
A 55-year-old man suffered from dyspnea, general malaise, and jaundice. His laboratory date showed pancytopenia and hemolytic anemia, and computed tomography showed splenomegaly. Bone marrow examination revealed myelofibrosis (MF)-1. The hemolytic anemia was diagnosed as IgM autoimmune hemolytic anemia (AIHA) with negative direct and indirect Coombs test but positive IgM-direct antiglobulin test. We started ruxolitinib 20 mg, which improved not only bone marrow fibrosis, symptoms related to myeloproliferative neoplasms and splenomegaly, but also AIHA. AIHA may be associated with Autoimmune MF (AIMF), and cytokines such as transforming growth factor (TGF)-β are thought to be involved in such cases. This case suggests that ruxolitinib may improve the cytokine levels and may lead to the treatment of AIHA as well as AIMF.
TBX15/miR-152/KIF2C Pathway Regulates Breast Cancer Doxorubicin Resistance Via Promoting PKM2 Ubiquitination
Authors: Jiang Cheng-Fei , Xie Yun-Xia , Qian Ying-Chen , Wang Min , Liu Ling-Zhi , Shu Yong-Qian , Bai Xiaoming , Jiang Bing-Hua 
Published: September 2021

Abstract
Background: Chemoresistance is a critical risk problem for breast cancer treatment. However, mechanisms by which chemoresistance arises remains to be elucidated. The expression of T-box transcription factor 15 (TBX-15) was found downregulated in some cancer tissues. However, role and mechanism of TBX15 in breast cancer chemoresistance is unknown. Here we aimed to identify the effects and mechanisms of TBX15 in doxorubicin resistance in breast cancer.Methods: As measures of Drug sensitivity analysis, MTT and IC50 assays were used in DOX-resistant breast cancer cells. ECAR and OCR assays were used to analyze the glycolysis level, while Immunoblotting and Immunofluorescence assays were used to analyze the autophagy levels in vitro. By using online prediction software, luciferase reporter assays, co-Immunoprecipitation, Western blotting analysis and experimental animals models, we further elucidated the mechanisms.Results: We found TBX15 expression levels were decreased in Doxorubicin (DOX)-resistant breast cancer cells. Overexpression of TBX15 reversed the DOX resistance by inducing microRNA-152 (miR-152) expression. We found that KIF2C levels were highly expressed in DOX-resistant breast cancer tissues and cells, and KIF2C was a potential target of miR-152. TBX15 and miR-152 overexpression suppressed autophagy and glycolysis in breast cancer cells, while KIF2C overexpression reversed the process. Overexpression of KIF2C increased DOX resistance in cancer cells. Furthermore, KIF2C directly binds with PKM2 for inducing the DOX resistance. KIF2C can prevent the ubiquitination of PKM2 and increase its protein stability. In addition, we further identified that Domain-2 of KIF2C played a major role in the binding with PKM2 and preventing PKM2 ubiquitination, which enhanced DOX resistance by promoting autophagy and glycolysis. Conclusions: Our data identify a new mechanism by which TBX15 abolishes DOX chemoresistance in breast cancer, and suggest that TBX15/miR-152/KIF2C axis is a novel signaling pathway for mediating DOX resistance in breast cancer through regulating PKM2 ubiquitination and decreasing PKM2 stability. This finding suggests new therapeutic target and/or novel strategy development for cancer treatment to overcome drug resistance in the future.