bluuebunny/crossref_metadata_2025_split huggingface dataset:
Screening New Formulations for Asphaltene Aggregation Inhibition
Authors: Al-Jabri Jaber , Sultan Abdullah , Al-Mutairi Eid , Onaizi Sagheer A. , Merghani Amir , Hassen Islam 
Published: October 2018

Abstract
Asphaltene aggregation is one of the biggest problems in the oil and gas industry for both upstream and downstream processes. It called the cholesterol of crude oil since it can deposit on the reservoirs pores and block it. It can also plug the production tubes and pipelines which could cost millions of dollars. One of the solutions is adding different chemicals such as asphaltene dispersants (ADs) or asphaltene inhibitors (AIs). ADs reduce asphaltene particle size which will keep them in the crude while AIs prevent the asphaltene aggregation by shifting the onset pressure of asphaltene.
In this paper, three different asphaltene inhibitors were tested and investigated thoroughly with different concentrations for heavy Arabian crude oil. Several tests were performed: asphaltene inhibitors efficiency was tested using laser scanner analysis and asphaltene stability was investigated by using spot test method and asphaltene solubility class index.
The results showed that the Arabian crude oil has a high asphaltene content and it reasonably stable. Two of the inhibitors (SF-1742 and AI-410) have showed better efficiency than the third inhibitor (AI- 108) in the inhibitors efficiency test with low optimum concentration.
Full Wavefield Modeling in Anisotropic Media
Authors: Alshuhail Abdulrahman , Golikov Pavel 
Published: October 2018

Abstract
With the increase in accuracy required for seismic exploration one must include more physics in modeling seismic waves. In this paper we extend Full Wavefield Modeling (FWMod) to handle anisotropic media. FWMod is an integral-based approach that model's reflection events. It considers primary as well as multiple scattered reflections. We make use of the pseudo-elastic assumption for the acoustic wave-equation for anisotropic media to simplify the equations and reduce the cost associated with modeling. This introduces anisotropic kinematics into the acoustic wave equation, however this comes with two main limitations.
The first limitation is that a pseudo S-wave is generated when the source is on, or near, an anisotropic layer. The pseudo S-wave manifests as a diamond shaped shear wave. The second limitation is an exponential growth in the solution for negative values of η. Attenuating these artifacts in finite-difference modeling is difficult and, in many cases, suboptimal. However, with a phase shift method such as FWMod attenuating these limitations is relatively straightforward.
The pseudo S-wave can be clearly recognized in the absolute value of the phase shift extrapolator. In this domain it can be identified and attenuated. As for negative values of η, with this type of representation of the extrapolators, one can ensure that we always have evanescent decay rather than exponential growth in the solution. We include the anisotropic kinematics in the FWMod formulation and demonstrate the effectiveness of this method using a synthetic model.
Substitute CRMs for Quality Control Purposes With In-House QCM
Authors: Hzzazi Salem Ahmed , Qmous Abdullah 
Published: October 2018

Abstract
The Southern Area Laboratories Division (SALD) is accredited the ISO/IEC 17025 and is currently implementing a QA/QC program in all Units as part of the Laboratories quality management to monitor and validating of tests results.
Results of quality control analysis are aimed to provide clear and fast information for the Acceptance of analytical results obtained on a batch of test samples. Continuous use of control Material allows estimation of the stability of performance of the instrument, including calibration, Analytical procedure, analyst, and influence of environmental conditions.
Matrix is one of most common interference that effect choosing appropriate QA. The certified reference material (CRM) is not available at all (matching neither matrix nor measured), in additional to that the CRM is too costly to be used for quality control of a larger number of analytical test runs.
For that reason we conducted a study for the water samples collected from the different locations in the field for geo- chemical studies over a period of times to prepare QC for geo-chemical analysis.
Fluid Typing Using Magnetic Resonance Data with High Diffusivity
Authors: Oifoghe Stanley , Sy Rex , Okowi Victor 
Published: October 2018

Abstract
Magnetic resonance (MR) data were acquired in a six-frequency PoroPerm + Light Oil mode in the study well. The acquired data had a low signal-to-noise ratio from midpoint to the top of the logged interval. This ratio could adversely affect the suitability of this data for hydrocarbon fluid typing and saturation computation.
Examination of the detailed quality control plot showed high B-pulse ringing on the two lowest and the third highest frequencies, A-pulse ringing on the two lowest frequencies, and noise on the two lowest frequencies. The affected frequencies could not be used for fluid typing analysis. The reduction in the total number of available frequencies resulted in a high diffusivity, especially in the gas-bearing reservoir sand. High diffusivity caused some of the movable fluids to appear as irreducible bound water. The low hydrogen index of the gas also caused a low-permeability profile.
Despite the failure of some of the acquired frequencies, there was a need to identify and quantify the fluid type in the reservoir. Several fluid-typing techniques where employed to find a suitable technique for this dataset. After trying Multiple Gradient Inter-Echo Time (MGTE) analysis, the Simultaneous Inversion of Multiple Echo Trains (SIMET) module, and a 2D NMR (D-T2) technique, we decided to use D-T2 analysis because it gave results consistent with the gamma ray and density neutron logs. The D-T2 Analysis module is a software implementation of the 2D/3D NMR technique that solves for the T2 and D, or T1 /T2, T2, and D distributions from wireline magnetic resonance data. Often the results are shown in 2D image form by summation of the individual images having different T1 /T2.
The fluid typing result from D-T2 analysis showed the presence of gas and light hydrocarbon. The gas had an average saturation of 70%, while the oil had an average saturation of 65%. The oil viscosity varied slightly with the overburden gradient, increasing from 0.36cP at the top, to 0.55cP at the bottom. Although the resistivity-based saturation was not compared with the MR-derived saturations, the saturation result and other computed results match the average reservoir properties of offset wells within the vicinity of the study well. The results are also consistent with the gamma ray and density neutron logs.
Derived Equation for Skin Due to Restricted Fluid Entry into ICD
Authors: Uche Chukwunonso Ifeanyi , Obah B. , Onwukwe S. , Anyadiegwu C. , Boluwatife O , Bukar I. , Uche Jennifer 
Published: October 2018

Abstract
The use of inflow control devices (ICD) have been used to balance flux around wellbores and also delay breakthrough of unwanted fluid into completions.1-2. Inflow-control devices (ICDs) were developed to avoid coning problems in long horizontal wells. The model for the ICD consists of pressure-drop equations from the reservoir, through the screen, the flow conduit, the ICD nozzle, and into the production tubing, along with pressure drop through the lower-completion system.1-2. This technology has been a common practice in the petroleum industry for many years now. This procedure though has been beneficial especially in highly heterogenous small formations, but however causes some pressure drop which does not contribute to additional fluid inflow into the wellbore and this is seen to be an impairment to the productivity of horizontal wells to some extent. In wells that are equipped with ICD, a precise quantification of this additional pressure drop is of paramount importance to completely identify the existence of damage created around the well bore. Many authors have proposed mathematical solutions that can be used to estimate various pseudoskin factor caused by damage, partial completion, slanted well and perforation. No author has researched about productivity loss or skin that may result from the use of inflow control devices. In this work, a 3D numerical model which includes inflow control devices along horizontal wells was used to investigate reservoir and production performances of various ICD nozzle sizes. Different productivity losses from different nozzle sizes were seen as skin. Consequently, a simple equation for calculating this skin due to restricted fluid entry through ICD nozzles was derived. The skin results obtained from this new equation is compared with the result obtained using existing skin equation and the variance is within acceptable limit.
Techniques for Effective Oil Production from Thin Oil Rim Reservoirs
Authors: Ogolo Naomi Amoni , Molokwu Victor C. , Onyekonwu Mike O. 
Published: October 2018

Abstract
There are several proposed techniques that can improve oil recovery efficiency from thin oil rims with strong aquifers and large gas caps. These techniques include use of horizontal wells, water production from the underlying aquifer, edge water injection into the oil zone and gas injection at the oil water contact (OWC). Since all these methods improve oil recovery from thin oil rims, one of the objectives of this work is to investigate by simulation, the effect of combining two methods on recovery efficiency of the reservoir. The dynamics of the fluid contacts for all the techniques considered were also studied and it was observed that the most minimal shift occurred with the technique of gas injection at the OWC.
Simulation results revealed that combining two techniques does not significantly improve oil recovery efficiency over one technique. When only a single technique was used, the oil recovery factors were 40%, 33% 44% and 42% for water production and disposal, edge water injection, gas injection at the OWC and water injection at the gas oil contact (GOC) respectively. But on combining two techniques of simultaneous water and gas injection at the GOC and OWC respectively and alternate water and gas injection at the GOC and OWC respectively, the oil recovery efficiency were 43% and 45% respectively. These results indicate that any increase that might occur may not be significant enough to justify the cost of implementing two or more techniques; thus, optimizing a single technique is recommended.
Experimental Investigation of Potential of Combined Controlled Salinity and Bio-Surfactant CSBS in Enhanced Oil Recovery EOR Processes
Authors: Udoh Tinuola , Akanji Lateef , Vinogradov Jan 
Published: October 2018

Abstract
In this study, we investigate potential application of environment-friendly bio-surfactants (EFBS) in EOR processes. We assess the prospect of combining the EFBS with controlled salinity (CS) water injection in optimising oil recovery using rhamnolipid and protein-enzyme as case study. Rock component analysis, bio-surfactant solubility in brine of varied concentration and composition, crude oil-brine interfacial tension (IFT) and bio-surfactants emulsification activity test were carried out as part of the preliminary investigations. Following these preliminary analyses, a series of comprehensive core flooding displacement experiments were used to investigate the EOR potential of CSBS injection process. Finally, effluent analyses were conducted to study the effect of this combined process on dynamic oil-brine-rock interactions. Results of the IFT tests using 0.0083-3M brine concentrations show IFT reduction from 3.40-2.5 mN/m with increasing salinity for protein-enzyme while increase in IFT from 0.11-0.34mN/m was observed with increasing salinity for rhamnolipid. However, using a fixed brine concentration of 8.3mM with varied bio-surfactant concentration, IFT reduction with increase in concentration was observed for both of them. Also, the two bio-surfactants exhibited stable emulsion active in varied brine salinity investigated. Protein-enzyme is soluble in varied brine formulation while rhamnolipid solubility was found to be dependent on the brine composition and system pH rather than the ionic strength. Furthermore, from the secondary injection of CS and CSBS, the highest recovery factor of 82.76% was achieved with CSBS (protein-enzyme). However, in the tertiary applications, the highest recovery of 83.40% was achieved in the CS injection. Finally, increased pH, Ca2+ and Mg2+ concentrations was observed with both CS and CSBS flooding. This suggests reaction between excess cations and previously adsorbed carboxylic group of crude-oil led to increased recovery. Whereas, at residual oil saturation, interaction between bio-surfactant molecules and rock surface resulted in increased water-wetness and release of oil.
Innovative Approaches to Successful Narrow Margin Drilling in Deepwater: Planning and Execution Strategies
Authors: Ayodele Adetokunbo 
Published: October 2018

Abstract
Drilling operations in a deepwater environment is faced with several challenges in all phases, and the most common types of drilling problems encountered in deepwater are similar to those found in shallow water or land. Although water depth in itself does not create new sets of problems, it however introduces additional complexities and limits problem-solving options in some instances. The most notable of these complexities is the narrow pore pressure/fracture gradient margin that is frequently encountered in deepwater environments.
The complexity of narrow margin is compounded in mature fields as depletion occurs, regardless of the production support mechanism. In extreme cases, the safe drilling window is narrower or non-existent, and as such necessitates appropriate mud weight selection and careful control of Equivalent Circulating Densities (ECD). Low mud weight can result in a kick or wellbore instability when the radial stress acting on the wellbore is insufficient. On the other end of the spectrum, high mud weight can cause formation fracture, exposing the wellbore to losses and well control event if not properly controlled.
In the late life of the field, it transcends and exceeds the application of conventional drilling methods to deliver an economically viable deepwater well. While drilling with the added complexity of a narrow drilling margin in mature fields, conventional methods tend to be inefficient and cost-ineffective and as such changes in the magnitude of a paradigm shift are required.
This paper presents some innovative approaches that can be employed in managing narrow margin drilling from the planning to execution phase of well delivery. It shows the collaboration and contribution of a cross-functional team in the planning phase, implementation of advanced drilling practices during execution phase and post drill optimization methods to deliver wells safely and within approved budget.
Performance Evaluation as a Tool for Improving Health, Safety and Environment Culture in the Oil Servicing Industry
Authors: Anyanwu Brilliance O. , Elijah Esuuk , Akakranta Onyewuchi 
Published: October 2018

Abstract
The study focused on evaluating the Health, Safety and Environment (HSE) performance of selected Oil servicing companies (X, Y and Z) engaged in Logistics, Mud logging and Engineering services respectively in Rivers State, Nigeria. This aim was achieved by determining the awareness level of Health, Safety and Environment Management System (HSE MS) and performance/practice level of HSE MS respectively.
Two sources of data were both used in this study. The primary source were from questionnaires distributed to 150 participants, out of which 120 were retrieved from 42 participants in company X, 40 in company Y and 38 in company Z representing 80% response rate. The awareness and performance levels of HSE MS were assessed with ten questionnaire parameters each respectively and their judgments rated Yes (3), No (2) and Undecided (1). This Likert approach was to facilitate the evaluation of Kendall's coefficient of concordance (W), representing the concordance level among participants.
The results revealed average levels of awareness (79%) and performance/practice (64%) of HSE MS respectively among the companies except for company Z. Gaps identified included lack of awareness on what governs the integrated HSE MS, lack of provision of hygienic environment and non-availability of safe equipment and PPE. Company Z had deficiencies in providing a good system for communicating HSE issues, providing permit to work (PTW), conducting HSE induction/training, providing incident reporting procedure, ensuring contingency plans are made available and maintaining a good system for managing employee's health. The secondary data source were from the HSE MS Audit unit of the companies selected which showed that company X had an overall performance of 77% which indicated a good level, company Y had an overall performance of 64.3% which is a fair level and finally, company Z had 30% performance level which is unsatisfactory. Kendall's analysis showed a high level of agreement on both awareness (0.90) and performance (0.99) levels respectively.
The study recommends training of employees, provision of an environment with good hygienic conditions, and provision of safe equipment and personal protective equipment (PPE) for all companies. Provisions for contingency plans permit to work (PTW), and HSE review meetings should be emphasized by company Z. The findings and recommendations of this research will be a yardstick to these companies and other related companies in implementing HSE MS as business integration in quality and risk management.
Automation of Electrofacies Identification - A Case for Digitalization
Authors: Isimbabi Onoze A. 
Published: October 2018

Abstract
The 21st century is a period of rapid advancement in technology and the ever adapting and perhaps proactive companies will be the companies of the future. Advancement in science and in this case 3D reservoir modelling requires the automation of repetitive and mundane tasks to liberate human resources for evaluations and actual problem solving.
3D reservoir modelling is the digital representation of the subsurface in other to predict the behaviour of fluids in the reservoir, and a facies model is key to building a robust 3D reservoir model, as it provides the geometry and relationship of the reservoir sub units. The identification of facies in reservoirs as an input to building reservoir models is done using several data types including core data, seismic data, and well logs. This study focuses on the use of well logs in the identification of facies (electrofacies).
Electrofacies are facies defined using a set of well-log responses that characterize a lithologic unit and distinguishes it from others. Standard Industry practice has established the use of gamma ray log signature as predictors of facies and it is this relationship that is explored in this study. In 3D reservoir modelling, the process of facies identification and painting the facies into discrete logs is a repetitive and sometimes harrowing process - especially in a field with several stacked reservoirs and well penetrations. This process takes up valuable time in 3D reservoir modelling and the monotony can also lead to errors that may have a significant impact on the facies model eventually built. At present, the automation available in modelling tools is only able to identify facies using absolute log values; this only discriminates between sandstone and shale in clastic reservoirs.
In this study, I present an excel-based application that can ‘recognize’ log shapes and as such, can identify up to five distinct facies: Channel Sands, Upper Shoreface, Lower Shoreface, Heteroliths and Shale in shallow marine settings. This application has been deployed to build a 3D static model for field development planning for the Debby field, Onshore Niger Delta. Significant results were achieved with execution of facies identification and discrete log creation taking less than 5% of the time it would typically take for manual electrofacies definition. This ensured more time availability for important and productive tasks such as uncertainty analysis, sensitivity analysis, and creation of more recovery scenarios.
Numerical Simulation of Polymer Flooding in a Heterogeneous Reservoir: Constarained versus Unconstrained Optimization
Authors: Ibiam Emmanuel , Geiger Sebastian , Almaqbali Adnan , Demyanov Vasily , Arnold Dan 
Published: October 2018

Abstract
The average global recovery factor of a typical oil and gas field is approximately 40% at after secondary recovery processes such as gas lifting and water flooding. The low recovery factor is often a result of by passing a considerable amount of oil in the reservoir due to unknown reservoir heterogeneity and incomplete understanding of the geology. Enhanced oil recovery (EOR) methods will play a key role in increasing recovery factors from existing reservoirs. Heterogeneous reservoir sands often show permeability contrast between layers and therefore lead to early water breakthrough when water flooding. In such situations, polymer flooding can potentially be a suitable EOR technique that helps to lower water cut and increase recovery. The addition of polymers to the injected water lowers the mobility ratio, thereby reducing viscous fingering and delaying water breakthrough.
This study investigates how a polymer flood design can be optimized while considering geological uncertainty in the reservoir models as well as modelling decisions. We applied an adjoint based technique to match data from a prolonged waterflood in the Watt Field, a synthetic but realistic clastic reservoir that is based on real data and captures a wide range of geological heterogeneities and uncertainties through a range of different model scenarios and model realizations. We apply Latin hypercube experimental designs with the Particle Swarm Optimization algorithm in CMOST. This was used to build a proxy model employing polynomial regression for the optimization of the engineering parameters to maximize NPV. The optimization were performed for both history-matched models (constrained optimization) and the original, non-history-matched models (unconstrained optimization). The aim of this work is to analyse how geological uncertainties inherent to a heterogeneous clastic reservoir as well as modelling decisions impact the design and performance a polymer flood. We further investigate how the different optimization methods impact the predicted reservoir performance and optimal design of the polymer flood.
Our findings show that both, geological and engineering uncertainties, impact polymer flooding and that designing the right well controls is essential for successful polymer flooding. Shale cut-offs are identified as a key petrophysical uncertainty when optimizing a polymer flood in a heterogeneous clastic reservoir. Furthermore, forecasts using constrained optimization yielded a much narrower range of incremental oil recovery and NPV during polymer flooding and may underestimate both, risk and opportunities for polymer flooding because the history matching of the water flood emphasizes different geological features compared to the way geology interacts with a more viscous polymer solution.