bluuebunny/crossref_metadata_2025_split huggingface dataset:
Completion Study Aims To Extend Life of Electrical Submersible Pumps
Authors: Carpenter Chris 
Published: November 2021

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper IPTC 20130, “Practical Approach for Solid Production Prediction and Completion Strategy Decisions in Horizontal Wells: A Case Study From a Cretaceous Carbonate Reservoir, North Oman,” by Mohammed Al-Aamri, Sandeep Mahajan, SPE, and Nair Sujith, Petroleum Development Oman, et al., prepared for the 2020 International Petroleum Technology Conference, Dhahran, Saudi Arabia, 13–15 January. The paper has not been peer reviewed. Copyright 2020 International Petroleum Technology Conference. Reproduced by permission.
The carbonate reservoir fields in Oman discussed in the complete paper are produced by several horizontal wells from long openhole sections. The wells are completed by barefoot (openhole) completion with electrical submersible pumps (ESPs) located in the wells’ buildup section. The field has experienced significant ESP failures, so a study aimed to provide input for well-completion-strategy design and operational parameters, which could minimize solids production and lower intervention/operating expenditure (OPEX). Based on the study results, recommendations were provided for a drawdown-management strategy, which potentially will benefit from increasing ESP run life and reducing field OPEX.

Field Background

Problem Statement and Motivation
Petrophysical rock typing for the studied reservoir is detailed in the complete paper. The primary understanding of the root cause of these ESP failures was argillaceous rock typing along the horizontal section. The decision was made to recomplete the wells by isolating equipment from such rock typing. As a result, ESP run lives improved, but failures continued. Several wells featured an isolation process from the first day, for example, but run life did not improve.
The field team subsequently analyzed a sample of fines taken from the ESP, and their mineralogy was examined. The main finding was that almost 50% of the sample included calcite mineral content with some quartz (Fig. 1). However, the question remained as to which part of the reservoir the sample belonged.
All rock types potentially consist of such calcite minerals because of the marine-deposition environment. Hence, investigating and characterizing the possible root causes of the ESP failures, as well as providing effective completion mitigations for upcoming wells, was critical.
The key objectives of the study were to understand the mechanisms and causes of the observed solids from a geomechanical standpoint and to provide recommendations to minimize the risk of near-wellbore failure.
Novel Resin-Cement Blend to Improve Well Integrity
Authors: Wagle Vikrant , Al-Yami Abdullah Saleh , AlKhalaf Sara , Alanqari Khawlah Abdulaziz , Ali Wajid , Al-Turki Faisal Abdullah 
Published: November 2021

Abstract
A good primary cementing job governs in a great part the producing performance of a well. Successful zonal isolation, which is the main objective of any cementing job, primarily depends on the right cement design. The resin-based cement system, which is a relatively new technology within the oil industry has the potential to replace conventional cement in critical primary cementing applications.
This paper describes the lab-testing and field deployment of the resin-based cement systems. The resin-based cement systems were deployed in those well sections where a potential high-pressure influx was expected. The resin-based cement system, which was placed as a tail slurry was designed to have better mechanical properties as compared to the conventional cement systems. The paper describes the process used to get the right resin-based cement slurry design and how its application was important to the success of the cementing jobs. The cement job was executed successfully and met all the zonal-isolation objectives. The resin-based cement's increased shear bond strength and better mechanical properties were deemed to be instrumental in providing a reliable barrier that would thwart any future issues arising due to sustained casing pressure (SCP). This paper describes the required lab-testing, lab-evaluation, and the successful field deployment of the resin-based cement systems.
Electrochemically Assisted Deposition of Calcium Carbonate Surfaces for Anionic Surfactant Adsorption: Implications for Enhanced Oil Recovery
Authors: Liu Zilong , Onay Hayati , Guo Fengzhi , Hedayati Pegah 
Published: November 2021

Abstract
Surface roughness of rocks had a significant influence on surfactant adsorption in enhanced oil recovery (EOR), both in terms of the total amount adsorbed as well as of the kinetics of adsorption. Combining electrochemical techniques and quartz crystal microbalance with dissipation monitoring (QCM) into one analysis setup opens up new avenues for depositing model rock surfaces and investigating the adsorption behavior. Using electrochemically assisted deposition, uniform and well-covered metal-CaCO3 sensors were obtained to simulate rough carbonate rocks and characterized by scanning electron microscope with energy dispersive X-ray analysis (SEM-EDX). The deposition process was controlled by the nitrate and oxygen electroreduction reactions in the presence of bicarbonate and calcium ions. The deposited mass of CaCO3 was calculated and the coverages for Au-CaCO3 and Pt-CaCO3 sensors were between 20 - 60%. It is observed that mostly cubic-like CaCO3 crystals were formed with crystal sizes around 20 to 50 µm from the SEM micrographs. The bigger crystals were surrounded by bare regions of Pt surface, suggesting the existence of Ostwald ripening process.
Prior to the investigation of the deposited CaCO3 surfaces, the adsorption of anionic surfactant alcohol alkoxy sulfate (AAS) was studied on a smooth commercial CaCO3 surface with varying pH and CaCl2concentrations using QCM. Subsequently, surfactant adsorption was performed on the rough deposited CaCO3 surfaces and their adsorption behavior were compared. On a smooth CaCO3 surface, a fast adsorption of AAS surfactant was observed, whereas the desorption process was characterized as a two-step process. Compared to the smooth CaCO3surface, an increase of the frequency shift of about 5 times was observed on the deposited CaCO3 surfaces. This observation was mainly ascribed to the rougher surfaces, having more adsorption sites for AAS binding, and also the liquid trapping effect, resulting in more frequency shifts. It is suggested that a rough model mineral surface could be a better representation of a rock surface, presenting the implications of the new understanding for surfactant adsorption on different rock surfaces in EOR.
Next Generation High Performance Invert Emulsion Drilling Fluids with Flat-Rheological Behavior
Authors: Santra Ashok , Patel Hasmukh , Shanmugam Sivaprakash 
Published: November 2021

Abstract
The rheological properties of drilling fluids are crucial parameters for efficient drilling operations. Invert emulsion drilling fluids are the industry's preferred choice when it comes to extreme conditions like deepwater or high temperature and high pressure (HTHP) drilling due to their inherent thermal stability and effectiveness against water sensitive formations. In addition, another highly desired property of such drilling fluids is minimal sensitivity of the fluid flow properties for a wide range of application temperatures, known as flat-rheology behavior.
We have developed four novel and next generation chemical additives: (i) a high temperature stable emulsifier, (ii) a low-end rheology modifier, (iii) a viscosifier with covalently linked organic groups, and (iv) a fluid loss control additive. Molecular architectural designs and synthesis of all four chemicals were carried out in our laboratory and used in optimum quantities to build industry's next generation invert emulsion fluids at density ranges from 75 – 135pcf (10-18ppg) and application temperature range of 60-450°F. Rheological and other important drilling fluid properties were tested at different downhole pressures and temperatures using a standard API recommended HTHP apparatus.
The results demonstrated extreme thermal stability all the way from 60-450°F with excellent fluid loss control and ultrathin filter cake. The novel covalently-linked organophilic viscosifier used herein has proven superior thermal stability compared to existing organo-clay based systems especially at temperatures above 350°F. Novel secondary emulsifier and low-end rheology modifier have demonstrated excellent emulsion stability at temperatures up to 450°F. It has been an industry challenge to obtain true flat rheological behavior under high pressure and temperature using commercially available chemistries. However, very interestingly, fluids optimized in this work have exhibited excellent flat-rheological behavior for a wide range of temperatures. We will present a comparative analysis of the relationship between molecular structure and properties perspective of what is currently used in the industry versus those developed in this work.
The current work has led to development of four novel chemical additives which are responsible for the industry's next generation high performance invert emulsion drilling fluids with flat-rheological behavior.
An Experimental Study Investigating the Impact of Miscible and Immiscible Nitrogen Injection on Asphaltene Instability in Nano Shale Pore Structure
Authors: Elturki Mukhtar , Imqam Abdulmohsin 
Published: November 2021

Abstract
Miscible gas injection has become the most used enhanced oil recovery (EOR) method in the oil and gas industry. The deposition and precipitation of aspahltene during the gas injection process is one of the problems during the oil production process. The asphaltene can deposit and plug the pores, which reduces the permeability in a reservoir; thus, decreasing the oil recovery and increasing the production costs. This research investigates the nitrogen (N2) miscible and immiscible pressure injections on asphaltene instability in shale pore structures. First, a slim-tube was used to determine the minimum miscibility pressure (MMP) of N2 to ensure that the effect of both miscible and immiscible gas injection was achievable. Second, filtration experiments were conducted using a specially designed filtration apparatus to investigate the effect of nano pore sizes on asphaltene deposition. Heterogeneous distribution of the filter paper membranes was used in all experiments. The factors studied include miscible/immiscible N2 injection and pore size distribution. Visualization tests were conducted to highlight the asphaltene precipitation process over time. The results showed that increasing the pressure increased the asphaltene weight percentage. The miscible N2 injection pressure had a significant effect on asphaltene instability. However, the immiscible N2 injection pressure had a lower effect on the asphaltene deposition, which resulted in less asphaltene weight percentage. For both miscible/immiscible N2 injection pressures, the asphaltene weight percentage increased as the pore size of the filter membranes decreased. Visualization tests showed that after one hour the asphaltene clusters were clearly noticed and suspended in the solvent of heptane, and the asphaltene was fully deposited after 12 hours. Microscopy imaging of filter membranes indicated significant pore plugging from asphaltene, especially for smaller pore sizes.
Mechanical Properties of API Class C Cement Contaminated with Oil-Based Mud OBM at Elevated Temperatures and Early Curing Time
Authors: Arbad Nachiket , Rincon Fernando , Teodoriu Catalin , Amani Mahmood 
Published: November 2021

Abstract
The catastrophic events faced by the Oil and Gas industry in the past depict the importance of maintaining the integrity of the well. The cement acts as a crucial barrier throughout the life cycle of the well. The contamination of the cement occurs due to inefficiency in cementing practices and operations. Experimental investigations have been done on the reduction in mechanical properties of different API class cement considering contamination with water-based mud and oil-based mud.
This study focuses on analyzing the changes in mechanical properties of API Class C cement on varying the following parameters:
OBM contamination (0%, 0.6%, 1.1%, 2.2%, 4.3%) Curing time (4 hrs, 6 hrs, 8 hrs, 1 day, 3 days, 7 days) Temperature (25˚C, 75 ˚C)
API recommendations were followed for preparing the cement slurries. The destructive, as well as non-destructive tests were carried out on the cement samples at ambient room temperature to measure the uniaxial compressive strength (UCS) for OBM contaminated class C cement slurries.
The general trend observed is that the UCS increases with an increase in curing time and temperature. UCS decreases with an increase in OBM contamination. Logarithmic trends were obtained for UCS vs curing time for different contaminations at a given temperature. Exceptions were observed at lower curing times where contaminated samples showed better results than the neat cement slurries. These observations play a critical role in understanding contaminated cement behavior.
This widespread work was carried out only on API Class C cement to provide reliable data for future references. The correlations presented in this paper will help operators estimate the deterioration in mechanical properties of Class C cement in the presence of low OBM contamination.
Email: nachiket.arbad@ou.edu & cteodoriu@ou.edu
Developments on Metal Sulfide Scale Management in Oil and Gas Production
Authors: Bhandari Narayan , Bhandari Manojkumar , Littlehales Ian , Potter Sean 
Published: November 2021

Abstract
Metal sulfide scaling issue in the oil and gas production continue to present significant flow assurance challenge. Recently, a novel polymeric chemistry that can effectively control FeS scale deposition in oil and gas production system was reported. However, how to manage finely dispersed FeS particulates at surface disposal facilities and whether this polymer is capable of mitigating ZnS and PbS deposition is largely unknown. Therefore, this study continues to seek an efficient treatment option for metal sulfide scale management.
Static bottle tests and dynamic scale loop tests under anoxic conditions were conducted to understand the efficacy of the novel polymeric chemistry towards metal sulfide scaling control. To mimic various field conditions; individual metal sulfide (FeS, ZnS and PbS) as well as mixed scaling scenarios were simulated. Various coagulant and oxidant chemistries were tested to understand the impact of the upstream treatment on safe disposal of FeS nanoparticles at surface facilities.
This novel polymeric chemistry was found to be not only effective towards FeS scaling control, but also towards dispersion of ZnS and PbS as well. The primary mechanism of metal sulfide scale deposition control is identified to be crystal growth inhibition and crystal surface modification. Laboratory test results indicated no negative impact of new chemistry on the performance of other chemicals (coagulant, oxidizer etc.). In fact, an enhanced efficiency of iron sulfide oxidation was observed possibly due to the large surface area of finely dispersed particles. A field throughput study results indicated superior performance compared to that of various incumbent chemistries.
Based on the laboratory results, it is anticipated that this chemistry will provide a new treatment option for metal sulfide scaling/deposition control. Additionally, the new chemistry did not leave any negative footprint for safe disposal of metal sulfide particulate at surface. As opposed to the calcite/barite scale, nucleation inhibition of metal sulfide may not be desired as the dissolved sulfide may cause further corrosion/deposition downstream. Therefore, the value this paper brings to the management of metal sulfides is a systematic testing and evaluation approach which confirms dispersion rather than nucleation inhibition is effective control mechanism.
Seawater Breakthrough Monitoring and Reservoir-Model Improvement Using Natural Boron
Authors: Wang Yanqing , Liu Zhe , Li Xiang , Xu Shiqian , Lu Jun 
Published: November 2021

Abstract
Natural geochemical data, which refer to the natural ion concentration in produced water, contain important reservoir information, but is seldomly exploited. Some ions were used as conservative tracers to obtain better knowledge of reservoir. However, using only conservative ions can limit the application of geochemical data as most ions are nonconservative and can either interact with formation rock or react with other ions. Besides, mistakenly using nonconservative ion as being conservative may cause unexpected results. In order to further explore the nonconservative natural geochemical information, the interaction between ion and rock matrix is integrated into the reservoir simulator to describe the nonconservative ion transport in porous media. Boron, which is a promising nonconservative ion, is used to demonstrate the application of nonconservative ion. Based on the new model, the boron concentration data together with water production rate and oil production rate are assimilated through ensemble smoother multiple data assimilation (ES-MDA) algorithm to improve the reservoir model. Results indicate that including nonconservative ion data in the history matching process not only yield additional improvement in permeability field, but also can predict the distribution of clay content, which can promote the accuracy of using boron data to determine injection water breakthrough percentage. However, mistakenly regarding nonconservative ion being conservative in the history matching workflow can deteriorate the accuracy of reservoir model.
Development and Application of a Novel Hydrogen Sulfide Scavenger for Oilfield Applications
Authors: Lehrer Scott , Jani Jagrut , Ramachandran Sunder , Liu Zhengwei 
Published: November 2021

Abstract
Currently used scavengers in mixed production applications can have issues with poor efficiency and thermal stability (triazines, glyoxal), scaling tendency (triazines), corrosivity (glyoxal), and emulsification (metal-based scavengers). Research was conducted which resulted in a new scavenger that avoids negative side effects while maintaining efficient performance over a wide range of applications. The application of this scavenger into mixed production can avoid or reduce the need for H2S removal post-separation, thereby reducing overall cost.
The development and field application of a new Hydrogen Sulfide (H2S) Scavenger in oilfield mixed production applications is presented. Several field applications will be discussed comparing the overall performance of this new H2S scavenger with existing technologies. Field application results will show that this novel scavenger avoids issues with currently used scavengers including poor efficiency, corrosivity, scaling, and emulsification. This new H2S scavenger technology is suitable for both surface and downhole injection. It will be demonstrated how removing H2S upstream in mixed production can save overall treatment cost.
Pore–Scale Numerical Investigations of the Impact of Mineral Dissolution and Transport in Naturally Fractured Systems During CO2–Enriched Brine Injection
Authors: You Jiahui , Lee Kyung Jae 
Published: November 2021

Abstract
CO2 storage and sequestration are regarded as an effective approach to mitigate greenhouse gas emissions. While injecting an enormous amount of CO2 into carbonate–rich aquifers, CO2 dissolves in the formation brine under the large pressure, and the subsequently formed CO2–enriched brine reacts with the calcite. Reaction–induced changes in pore structure and fracture geometry alter the porosity and permeability, giving rise to concerns of CO2storage capacity and security. Especially in the reservoir or aquifer with natural fractures, the fractures provide a highly permeable pathways for fluid flow. This study aims to analyze the acid–rock interaction and subsequent permeability evolution in the systems with complex fracture configurations during CO2 injection by implementing a pore–scale DBS reactive transport model. The model has been developed by expanding the functionality of OpenFOAM, which is an open–source code for computational fluid dynamics. A series of partial differential equations are discretized by applying the Finite Volume Method (FVM) and sequentially solved. Different fracture configurations in terms of fracture length, density, connection, and mineral components have been considered to investigate their impacts on the dynamic porosity–permeability relationship, dissolution rate, and reactant transport characteristics during CO2 storage. The investigation revealed several interesting findings. We found that calcium (Ca) concentration was low in the poorly connected area at the initial time. As CO2–enriched brine saturated the system and reacted with calcite, Ca started being accumulated in the system. However, Ca barely flowed out of the poor–connected area, and the concentration became high. Lengths of branches mainly influenced the dissolution rates, while they had slight impacts on the porosity–permeability relationship. While fracture connectivity had an apparent influence on the porosity–permeability relationship, it showed a weak relevance on the dissolution rate. These microscopic insights can help enhance the CO2 sealing capacity and guarantee environmental security.
Uncovering Mysteries of Waxphaltenes: Meticulous Experimental Studies of Field and Lab Deposits Unveil Nature of Wax-Asphaltene Intermolecular Interactions
Authors: Aguiar Janaina I. S. , Samouei Hamidreza , Mahmoudkhani Amir 
Published: November 2021

Abstract
In recent years, the utilization of modern sampling tools provided access to the field deposits from several offshore and onshore wells producing asphaltenic crudes. Compositional analysis of field deposits revealed the presence of asphaltenes and wax as major fractions, while system conditions traditionally implied precipitation and deposition of asphaltenes only. Most of the previous studies on organic deposition have been conducted with the key assumption that aggregation and precipitation of wax and asphaltene occur independently. A few researchers investigated the solubility parameter's alteration, but they did not incorporate waxes found in the oilfield deposits. This study aims to investigate the nature of "waxphaltenes"; from intermolecular interactions between asphaltenes and wax in samples collected from fields and made in the laboratory. Asphaltenes samples were extracted and fully characterized by proton nuclear magnetic resonance (NMR) and Fourier-transform infrared spectroscopy (FTIR). Paraffin waxes were identified using gas chromatography (GC), differential scanning calorimetry (DSC), NMR, and FTIR. Precipitation tests of asphaltenes with n-heptane at high temperature were performed both in the presence and absence of wax; GC, NMR and FTIR techniques evaluated the precipitates and the material dispersed in solution. It was found that asphaltenes co-precipitated with waxes even at higher temperatures than the normal wax appearance temperature (WAT) of the crude oil or the model solutions and that long and medium size paraffin waxes had higher tendencies to coprecipitate with asphaltenes than either short chain or very long chain paraffin hydrocarbons. The results also indicated that the amount of wax that co-precipitates with asphaltenes was more related to asphaltene structure but is independent of the asphaltenes or wax content. Heteroatoms played an important role in the interactions between wax and asphaltenes during precipitation and separation.