bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nanoparticles-Stabilized CO2/Brine Emulsions at Reservoir Conditions: A New Way of Mitigating Gravity Override in CO2 Floods
Authors: AlYousif Zuhair , Almobarky Mohammed , Schechter David 
Published: October 2018

Abstract
CO2 injection is an effective method for enhanced oil recovery (EOR). However, the efficiency of CO2 is hindered by mobility problems. The high mobility of CO2 compared with the reservoir fluids may lead to early breakthrough of CO2, resulting in an incomplete sweep. The use of surface modified nanoparticles has provided an excellent alternative to generate a stable CO2/brine emulsion for CO2 mobility control. The objective of this work is to investigate the effect of: emulsion quality, shear rates, salinity, pressure, nanoparticle concentration and nanoparticle size on the strength of the emulsion.
Glass beads as a porous medium and a capillary tube to measure the apparent viscosity were used to perform the tests at reservoir conditions. Three types of coated silica particles were used to conduct this study. Three qualities were tested: 50, 70 and 90%. Also, five shear rates were used to assess the strength of emulsions. Solutions with 1, 3 and 8 wt% of NaCl were used. The role of the nanoparticle size was also tested for one type of silica particles. The effect of these parameters was evaluated at high pressures (800 and 1800 psi) and temperature (50°C).
For all tested materials, the quality of the emulsion was found to be an important parameter for emulsion strength. Emulsion viscosity increases as quality decreases, which indicates that the strongest emulsion was achieved at 50% quality. For silica partially modified with methylsilyl, the results showed that the change of salinity has no effect on emulsion viscosity. However, the increase of salinity produced emulsions with higher viscosities for silica modified with Polyethylene glycol (PEG) and silica modified with an appropriate material. The shear rate has a significant impact on the behavior of the emulsion for silica modified partially with methylsilyl group and PEG. Also, the study showed that the change of nanoparticle size has no effect on the emulsion strength. The change in pressure, however, has a significant impact on the emulsion viscosity.
The use of nanoparticles to stabilize CO2/brine emulsion has the potential to mitigate the gravity override challenge in a CO2 flood. Long-term stability of nano-particle stabilized emulsion is a critical factor in selecting the appropriate emulsifying agent. This work improves our understanding of the effect of different parameters on the strength of emulsions which can be used to control CO2 mobility and, therefore, improve sweep efficiency.
Experimental Investigation on Co-Polymer Grafted Bentonite for Controlling Reservoir Conformance
Authors: Ahmed Abdelazim Abbas , Saaid Ismail Mohd , Ahmed Afaque , Hamza Mohammed Falalu , Umar Abubaker Abubakar , Aini Siti Qurratu' 
Published: October 2018

Abstract
A water-disperible particulate system has been widely used in many mature oilfields for reservoir conformance control. This paper discusses performances of a newly formulated grafted bentonite to reduce the permeability and build up flow resistance in highly permeable water channeling zones. In this study, effects of various salinities, different injection flow rates and shear rates were investigated in the laboratory to determine permeability reduction ratio and transport properties to improve reservoir conformance problems. A flow model was set-up using sandpack flooding system where the sandpacks were saturated with brine. Experimental results obtained revealed that the grafted bentonite is easily injected and gradually built flow resistance by particles straining, physical-chemical attachment, and swelling. The permeability reduction ratio increased with increasing salinity while it decreased with increasing velocities. A significant permeability reduction ratio was observed when 0.5 pore volume of grafted bentonite dispersed in 1% NaCl brine was injected into brine saturated sandpack column. These significant results highlighted new insights for successful applications of modified bentonite to improve reservoir conformance problems.
Determinations of Engineers Turnover Working for National Oil and Gas Companies in Egypt
Authors: Farahat Abdallah 
Published: October 2018

Abstract
In Egypt, during the past 20-year national petroleum companies has been facing high turnover among experienced engineers who leave without enough notification period. This caused a lot of technical, managerial problems, increase replacement cost, and nonproductive time. The paper purpose is to introduce a new frame work to study and control turnover and/or turnover's intentions of employees working in oil and gas industry especially public and joint venture sectors in Egypt.
The study presents studied various models of turnover in general and focuse on recent devoted models and studies developed for oil and gas industry especially countries with similarities in culture and employees' attitude like Egypt. This will help decision makers to ensure organization stability and performance.
The research introduces a model that is suitable for oil and gas industry, it suggests that job fit, alternative job opportunities and organizational factors are the most significant independent factors that affects turnover. In addition to moderating factors that influence the relationship between the turnover and the said independent factors like: job stress, organization culture, oil prices, managerial style, and payment and rewarding system.
This frame work is a seed for understanding turnover phenomenon, it may be applied in similar industries with the same characteristics like harsh working conditions. The proposed frame work shall help managers, decision makers and researchers to better understand turnover causal factors in gorilla industries like oil and gas.
Use of Advanced Process Control for Automating Conventional Oilfield Operations
Authors: Patel K. , Bakhurji A. , Salloum H. , Kim H. , Winarno M. , Mubarak S. 
Published: October 2018

Abstract
With the proliferation of Internet of Things (IoT) technology and IR4.0, digital information is becoming more integrated into our daily operations. Such a modality of operation allows all disciplines in an organization to collaboratively manage and operate their assets to achieve the maximum value of their assets. In this paper we describe one of the initiatives under the company's digital transformation strategy. It is a simple yet innovative application of Advanced Process Control (APC) that facilitates continuous optimization of the performance of Electric Submersible Pumps (ESP), to not only comply with the assigned production targets, but also to automatically meet the operational constraints. The successful implementation of this technology on multiple oil wells in an onshore oilfield has demonstrated significant power saving, and is expected to minimize premature failures and extend pump life.
An Integrated Study Focusing on Baffle Characterization and Development Optimization
Authors: Liu Shuangshuang , Wei Chenji , Gao Yan , Li Yong , Luo Hong , Liu Zhuo , Xiong Lihui , Zheng Jie , Lou Yuankeli 
Published: October 2018

Abstract
The Middle East carbonate reservoirs are mostly reef flat sedimentary complexes, which are high heterogeneous and have extensive baffles. It brings great challenges to the efficient development of such reservoirs. Focus on the problem, a method of describing baffle distribution conjunctively using static and dynamic data is put forward in this paper. The distribution of baffles in the target formation is characterized based on core observation, well loggings, image logs, etc. Then, their impact towards reservoir performance is evaluated based on production data and dynamic surveillance data. Based on the study, it is acquired that cementation mainly controlled the upper baffles and compaction controlled the lower. Generally speaking, permeability of baffle is higher in the crest area and lower in the flank area. Baffles are stably distributed throughout the reservoir, although their ability to block fluid flow varies from region to region. The existence of baffles and their ability to block fluid flow had impact to the development effect, so development optimization and scheme comparison carried out. The corresponding development strategies are proposed for reservoirs with extensive baffles. Injectors and producers with highly-deviated well-type will help establish effective displacement system and achieve better reservoir production, it can improve the development effect and enhance oil recovery. This study offers a comprehensive case study for engineers and geologists to better understand this reservoir, it also provides a methodology that can be referred when developing similar fields.
Innovative Mechanical Tapered Scab Liner Design and Deployment to Restore Well Integrity
Authors: Aljubran M. J. , Ombe E. M. , Alluhaydan A. S. , Thomas S. 
Published: October 2018

Abstract
The current oil and gas industry uncertainty encourages innovative, efficient, and simple drilling and workover solutions. Challenging and problematic formations cause various design complications and operational risk. These include lost circulation, well control incidents, high density drilling fluid systems, tool design limitations, etc. Such troubles can also lead to liner and casing leaks downhole and eventually undesired surface pressure buildups across the tubing-casing and casing-casing annuli.
The case study well was drilled and completed, but prior to production a tubing-casing annular pressure of 6,500 psi was recorded. With two liners in the well casing designs (4-1/2 in. and 7 in.), a well leak was suspected to be at the top of the 7 in. liner as it was laying across a deep and over-pressurized formation with a 152.5 pcf gradient. After commencing the workover operations and due to downhole leaks and washouts, the well had to be killed off-bottom with 160 pcf manganese tetroxide (Mn3O4) mud. The well was fully decompleted, except for the production packer, which was left in hole. Investigation and diagnostic operations showed leaking 7 in. liner body and liner top packer.
To repair the leaking 7 in. liner, the team introduced an innovative design with a 4-1/2 in. x 7 in. tapered scab liner to sting into the newly installed repair packer and extend above the existing 7 in. top of liner to set on the 9-5/8 in. casing, and so cover the leaks. A mechanical 7 in. x 9-5/8 in. hanger and liner top packer system was deployed to allow for cementing the scab liner then setting these mechanical tools, where hydraulically actuated systems were impractical. Due to the high kill mud density of 160 pcf, a special 165 pcf Mn3O4 -Hematite cement recipe was adapted. Despite the high slurry density, this formulation allowed for optimal mixing, pumping, and leak isolation operations.
This paper will highlight the case study well history and challenges leading to liner leaks while emphasizing the nature of the over-pressurized formation. It will demonstrate the mechanical tapered scab liner design and deployment procedures in comparison to the conventional scab and tie-back liner jobs.
Molecular Transport of Solutes and Ions Through Filter-Cake: Implications for Wellbore Instability and Formation Damage
Authors: Adewole Jimoh K. , Kazeem Taye S. , Oyehan Tajudeen A. 
Published: October 2018

Abstract
During drilling, the invasion of drilling fluid components into the formation can be a major source of operational challenges such as borehole instability and formation damage. Filter cake, which is formed by particles that are captured near the wellbore surface, allows the movement of some molecules while it restricts the others. The properties of the filter cake as well the composition of the filtrate which permeate through it are very important parameters that can be tuned to prevent possible operational challenges. In this paper, the transport properties of certain ions (sodium, potassium, magnesium and calcium) through bentonite- based drilling fluid filter cake were investigated. The effect of in-house activated clay particles on the transport properties was also investigated. The capability of the cake to control the transport properties of the permeating ions were measured in terms of ion rejection. The results obtained for the pure bentonite follows the sequence: Ca2+ &gt; Mg2+ &gt; K+ &gt; Na+. The trend was however, reversed by the addition of the activated clay to Mg2+ &gt;Ca2+ &gt;K+&gt; Na+. The avearge rejection for the pure bentonite cake for Na+, K+, Mg2+ and Ca2+ are 4.45, 49.64, 53.33 and 94.43%, respectively. The rejection results for the mixed-matrix cake containing the activated clay were 6.38, 51.34, 86.19 and 78.09 for Na+, K+, Mg2+ and Ca2+, respectively. It was observed that the selectivity of the filter cake for Mg2+ and Ca2+ was reversed due to the addition of the activated clay.
Propped Fracture Conductivity in Shale Reservoirs: A Review of Its Importance and Roles in Fracturing Fluid Engineering
Authors: Elsarawy Ahmed M. , Nasr-El-Din Hisham A. 
Published: October 2018

Abstract
Shale oil and gas developments have been growing dramatically in the U.S. since the successful development of the Barnett shale in the early 2000's. The industry was able to unlock the Barnett shale by coupling the technologies of both horizontal drilling and hydraulic fracturing. The experience stimulated the spread of this method to other fields which eventually led to the recent U.S. production boom. However, numerous underperforming wells draw attention to the importance of completion optimization to maximize hydrocarbon production from shale reservoirs. Several approaches for completion optimization have been developed; however, fracture conductivity is usually sacrificed to minimize the operational cost. The objective of this paper is to provide a comprehensive review that highlights the importance of fracture conductivity to hydrocarbon production from shale reservoirs and its potential roles in the fracture design process.
The reviewed simulation, laboratory, and field studies reveal the importance of improving fracture conductivity to maximize the reserve and well production performance in different shale formations. Reliance of well production on fracture conductivity is explained by its severe reduction at downhole conditions, in addition to, the improved effective formation permeability by the effect of the induced microfracture networks. The factors affecting the fracture conductivity at downhole conditions and its calculation complexity are explained.
The review also demonstrates the adverse effect of water on fracture conductivity in shale formations, through shale softening and proppant embedment mechanisms. The different approaches to select the fracturing fluid additives for an improved fracture conductivity are summarized in this review. To minimize the damage to the formation and the fracture conductivity, the use of water-alternative energized fluids is discussed.
This paper improves the understanding of the main factors affecting the success of shale hydraulic fracturing treatments. Hydraulic fracturing is the main key to ensure an optimum completion process which helps to maximize the production from unconventional shale oil and gas reservoirs.
Formation Evaluation of Magnetic Resonance Logging-While-Drilling Data Recorded at a High Rate of Penetration
Authors: Oifoghe Stanley , Thern Holger , Coman Radu , Okowi Victor , Sy Rex 
Published: October 2018

Abstract
Magnetic resonance (MR) logging-while-drilling (LWD) data have numerous petrophysical applications for reservoir characterization. Under certain conditions, a high rate of penetration (ROP) can affect the data quality of MR LWD T2 distributions, compromising some of the estimated petrophysical properties. Logging MR data at a low ROP was so far the recommended approach to ensure high MR data quality. Moreover, when high ROP could not be avoided, ROP effects were a reason to consider the MR data to be of very limited or no value.
Recently, an ROP correction for MR logging data was introduced. The correction on porosity is particularly significant for large volumes of light hydrocarbon (HC) with a large T1 value. For best results, the MR logging data should comprise an extended data set, e.g., including echo trains with full and partial polarization of the light HC that enables the calculation of an in-situ T1 of the light HC. Extended data are, however, often not available in older data sets—a condition not discussed in detail before.
This paper presents a case study based on MR data recorded offshore Nigeria many years ago. The well was drilled with an ROP exceeding 40 m/h, which was twice as fast as the typically recommended maximum ROP at the time. The logged reservoir has a porosity of 30 to 35 p.u., and it contains light oil and has a high oil saturation. The ROP polarization effect caused a severe porosity overestimation. At that time, no ROP correction was available, and the MR data were considered not suitable for petrophysical interpretation because of the porosity overestimation.
The recently introduced ROP correction was successfully applied to the log data using a constant T1/T2 ratio value for estimating T1 of the light HC from the acquired T2 distribution. The correction results show that the MR total porosity was severely overestimated without correction. However, the porosity overestimation was only related to an increase of the light oil porosity. The volumetrics and the T2 distribution of the irreducible fluid fraction remain unaltered by the correction.
Consequently, valuable information can still be extracted from the uncorrected T2 distribution. First, the uncorrected MR data enables a simple computation of saturation, which is in good agreement with the resistivity-based saturation. Second, the amount and position of the bound-water peak correlates to variations in rock type and quality. Third, the position of the light-oil T2 peak indicates variations in mineralogy, because it correlates well with variations in the gamma ray (GR) log curve.
Impetus and Impediments in the Nigerian Content Law: A Sabbatical Review
Authors: Olatoye Deji 
Published: October 2018

Abstract
The theoretical bases for the body of policies for the development and utilisation of local capacities in general or in specific industries – now generally referred to as ‘local content’ policies – are of long standing. Evidence of their existence has long been scattered in white papers and the statute books of developing countries. From international trade perspective, it partakes of the protectionism-competitiveness debate regarding the mediation of imported capital vis-a-vis domestic capital formation. That debate itself, however, begs the question as it presupposes the existence of a fairly formed local industry worth protecting. From the standpoint of the global value chain, a local content policy aims to help countries that traditionally occupy the head-end of inbound logistics in global industries gain on a longer stretch of the chain. Furthermore, from the perspective of industrial policy, it provides an option by which developing countries grow local participation in strategic industries – this time, through the empowerment of local enterprises rather than the agency of state holdings as in traditional in industrial policies. Prior to 2010, legislations in Nigeria are strewn with provisions that promote the systematic acquisition of technological and management skills, regulate the utilisation of expatriate workforce as well as prefer if not entirely preserve local participation in certain categories of businesses and professions. In recognition of the central role of oil and gas in the Nigerian economy, Nigerian Oil and Gas Industry Content Development Act (‘Nigerian Content Act’) was passed in 2010. Seven years after that landmark event, this paper reviews the virtual framework created by the pre-existing laws and highlight the novelty of the Nigerian Content Act and its proposed amendment. It concludes that, whilst many of the provisions of the Nigerian Content Act brought about a number of improvements to the subject matter, some others have potentials to tame the effectiveness of pre-existing laws. Since some of the confusions introduced by the latter category of provisions are largely due to poor draftsmanship, the paper also identifies some key provisions that could benefit from a second take by the draftsman.
Meta-Modeling Evaluation of the 2017 Petroleum Industry Fiscal Reform Terms on Deep Offshore Assets in Nigeria
Authors: Ojaraida Lolo , Iledare Omowumi , Akinlawon Adeyemi 
Published: October 2018

Abstract
Deep offshore hydrocarbon resource development in Nigeria is of great economic interest due to security challenges limiting direct investment flow to onshore petroleum assets. However, Petroleum fiscal systems, which basically describe the relationship between host government and International oil companies (IOCs), are paramount in the deep offshore investment decision process. This paper focuses on assessing the implications on deep offshore asset development economics under the 1993 Production Sharing Contract (PSC) terms in comparison to the fiscal terms in the 2017 petroleum industry fiscal policy reform report.
A metamodeling framework is proposed and applied in this paper. The framework adopted involves the development of deterministic cash flow models for both the 1993 PSC and the 2017 proposed fiscal terms. A range of profitability indicators for economic evaluation is generated and Monte Carlo simulation using @Risk software is applied to account for risks and uncertainties.
The results reveal that the 2017 fiscal terms appear to be favorable to the contractor based on selected profitability indicators. In addition, there is strong evidence to suggest that the dual tax system proposed in the 2017 fiscal policy is economically attractive to the contractor when compared to the single tax system in the 1993 PSC. Hence, deep offshore E&P development is expected to be more rewarding to contractor under the 2017 draft fiscal policy terms than the 1993 PSC terms, ceteris paribus.
Prototyping, Analysis of the Performance of a Beta Type Stirling Engine for Power Generation
Authors: Ajisafe Oluwagbenga 
Published: October 2018

Abstract
A stirling engine is prototyped after subjecting to computational analysis using Computer Aided Design and Development processes. The design objective includes; 37% efficiency and a power output of 1.5KW. The analytical processes utilizes Beale/West, Schmidt, Ideal, Adiabatic method as well as Simple Analysis for proper estimation of the engine's performances. The critical factors during the preliminary design process include; heat loss, dead volumes and pressure drops. Gaps between the regenerator and the seating, as well as high performance ceramic seals are introduced to reduce heat loss by conduction. Careful analytical processes and design were carried out to ensure a compromise that reduces pressure drops and dead volumes while reducing heat losses. The prototype was fabricated locally, and it demonstrated a wonderful design process.