bluuebunny/crossref_metadata_2025_split huggingface dataset:
Oil Rim De-Risking and Appraisal Value of Information in a Gas Reservoir
Authors: David Olayinka , Laoye Abiodun , Odegbesan Seyi , Isimbabi Onoze , Obeahon Percy 
Published: July 2016

Abstract
Millions of dollars are spent across the oil and gas industry on data gathering activities with a view to reducing subsurface uncertainties towards optimizing reservoir development and management. However, suboptimal attention is often paid to assessing the value of the information (VoI) during data acquisition requirement planning and before requesting for such information. The capital intensiveness of the industry and emerging low oil price regime has necessitated scrutiny on every dollar spent on data gathering in the current business terrain.
The application of the VoI concept in the oil & gas industry provides a predictive, analytic and quantitative framework for decisions and justifications for data gathering activities including but not limited to log data acquisition; downhole fluid sampling; subsurface diagnostic tests; core data acquisition; appraisal drilling and seismic acquisitions. Value of Information in simple terms is described as the amount a decision maker should be willing to pay for a piece of information. It is evaluated as the difference between the future value of a project given the availability of particular information versus its value without it.
This paper demonstrates the methodology and application of VoI analysis to support a key decision on whether or not to drill an appraisal leg of a well to test for fluid contact and possible presence of an oil rim in a reservoir prior to initial gas development. The major uncertainty in this study is the evaluation of the hydrocarbon extent in a gas reservoir with a gas-down-to (GDT). To evaluate the options, a VoI analysis was carried out by integrating results of different data sources; well log data; formation pressures; seismic data and analogue information. Integration of the different data was used to arrive at different subsurface realizations which fed into 3D static and dynamic simulation models. The modeling result for the different scenarios was used as input for economics in the VoI analysis.
Using the multiscenario analysis, the range of oil rim thickness proved to be non-commercial and the VoI analysis showed that drilling an appraisal will result in a negative value of appraisal giving the estimated VoI and cost of drilling an appraisal well. The analysis has led to significant cost saving of about $8million which is the appraisal cost of an earlier planned appraisal/development well. The analysis also helped to challenge the pre-existing appraisal paradigm and provided a robust basis for a commercial decision without compromising on regulator standards and industry best practices.
Predicting the Fluid Above Shallowest Known Oil SKO: Integration of PVT, Well Logs and Seismic - Limited Data
Authors: Awasthi Amit , Ikwueze Obinna , Itua Osazua J. , Tendo Fidelis , Osayande Francesca 
Published: July 2016

Abstract
For reservoirs that are not fully appraised, fluid type and resource volumes above Shallowest Known Oil (SKO) or Deepest Known Oil (DKO) are often unknown. This paper discusses the workflow adapted to predict the fluid type above the SKO with reasonable certainty. This enables to book SPE compliant resource volume (SCRV) above SKO to be proposed for booking and up dip wells to be justified.
As part of SCRV estimation for Field-X to book hydrocarbon volumes above the SKO, the oil properties, reservoir pressure data and seismic information were integrated utilizing the limitations and uncertainties around each data for the candidate reservoirs. The fluid properties (specifically bubble point pressure) are the most essential element in this analysis, which sometimes are not available or not of sufficient quality. This article will discuss the methodology and workflow adopted to use the existing limited information with their corresponding uncertainties to circumvent these limitations.
This methodology was demonstrated as a reliable technology supporting SCRV for Field X, resulting in the increase of ~ 25-30 % of the oil SCRV. Furthermore it has potential to be applied to other fields with similar circumstances.
Technical Assessment of In-Country Capabilities in the Oil and Gas Operations in Nigeria
Authors: Oriaku T. O. , Udo N. A. , Ifeduba E. A. 
Published: July 2016

Abstract
Building local capacity among indigenous oil and gas players is a non-negotiable mandate for the Nigerian Oil and Gas Industry. A technical evaluation was conducted to assess the capabilities of 33 indigenous companies rendering services ranging from Tubing Inspection Handling and Management Services, Slickline Operations and, Surface Well Testing Operations within the Warri and Port-Harcourt areas of the Niger Delta. The table top and facility inspection evaluations showed that, for the Tubing Inspection Services, 44% out of the 18 companies sampled scored the mandatory 60% minimum required to qualify technically. Surface well testing services showed 63% of the 8 companies scoring above 70% while Slickline services revealed 88% pass for the 8 companies sampled. Criteria used in the technical assessment of these companies include; equipment and materials availability, service delivery time, job experience, HSE standards, personnel, staff training and project management. This paper attempts to evaluate the technical capabilities of indigenous companies as well as highlight some of the challenges facing the local content initiative.
Integrated Surveillance in the Management of Decline on a North Sea Mature Field
Authors: Ogedengbe Allen 
Published: July 2016

Abstract
The purpose of this paper is to describe how integration of different well and reservoir surveillance methods on a mature field in the North Sea is used to deliver value. The surveillance plans for a mature North Sea field named Field X here broadly serves two purposes: Short term day-to day-data gathering for well operations, well work planning, voidage management and optimization.Use of longer term tools like seismic to identify bypassed pools of oil reserves in different parts of the field for optimization, well intervention and infill drilling.
A good surveillance strategy is a well thought out integrated plan which is fit for purpose for particular fields. This plan allows the field development plan to be delivered in an efficient and timely manner. The value of surveillance needs to be clearly articulated for all stake holders to allow a buy in for quality surveillance data. Future production delivery is tied to the quality of information obtained during data gathering.
Surveillance planning on Field X has been standardized to allow ease of use. The objectives of the surveillance planning to obtain data that will ensure safe well operations, enhanced well stock value. This process is kept simple, and allows for speed and flexibility during well work execution. The whole surveillance/intervention cycle integrates knowledge from a multi-discipline team from when ideas are generated, evaluated, approved, executed and stored.
Comparative Study of Rena and Mycoremediation Techniques in Reduction of Heavy Metals in Crude Oil Impacted Soil
Authors: Maduekwe C. , Nwachukwu E. O. , Joel O. F. 
Published: July 2016

Abstract
The comparative study of RENA, Mycoremediation and combination of the two techniques were carried out to determine their ability in the degradation of selected heavy metals (Cadmium, Chromium, Nickel, lead, Zinc, Manganese and Iron) in a Crude oil impacted soil. Three different plots for each technique and control were each spiked with 7.5 Litres of Bonny Light crude Soil Samples were taken at 0-15cm and 15-30cm depths for each of the techniques and control at 0, 4, 8, 12, 16 and 20 weekly intervals for heavy metal analyses. Results indicated that in the plots treated with RENA, Mycoremediation and combination of the two techniques, Lead (Pb) concentration was degraded by 55.9%,65.8%,85.1% respectively compared with control plots that gave 23.7% reduction of Pb. The percentage degradation of Manganese by RENA, Mycoremediation and Myco/RENA was 57.3, 64.3, 83.1 respectively while control plots recorded 26.1% Mn degradation. Concentration of Ni was reduced by 57.8% by RENA, 64.2%, by Mycoremediation and 85.6% by the combination of the two techniques (Myco/RENA) while in the control plots Ni was reduced by 27.89%. Concentration of Cd was reduced by 56.7% 65.6%, 88.7% by RENA, Mycoremediation and Myco/RENA respectively. The control plots recorded 26.1% Cd degradation. This was similar trend observed for other heavy metals studied. Thus the combination of the two techniques (Myco/RENA technique) gave a promising result in the degradation of all the heavy metals studied in Crude Oil Impacted soil.
Predicting Tubing Movement and Stress on Tubulars During Scale Remediation Jobs Using Computer Simulations
Authors: Ighalo Samuel , Romaine Keith , Andriessen Blake 
Published: July 2016

Abstract
Scale-squeeze remediation has been used extensively for removing scale from production strings in offshore and deepwater environments. During scale remediation treatments, the affected tubulars undergo displacement and stress that can affect the effective seal length and integrity of the completion system. Numerous laboratory simulations can be performed to help determine the effectiveness of the treatment fluids, injection volume, scale-inhibitor retention time, fluid composition, and shut-in time; however, sufficient research has not been conducted regarding the effects of these important parameters on the structural integrity of completion systems during an actual scale-inhibition squeeze treatment.
This paper studies the effects of these important parameters on completion system integrity by (1) performing wellbore thermal simulations of the treatment operations, (2) investigating how much tubing movement has occurred during these operations, (3) analyzing stress on the tubulars during different operations, (4) investigating the effects of scale-inhibition application methods on tubing movement, and (5) recommending a fit-for-purpose tubing movement workflow for the scale remediation process based on laboratory and field data.
This paper investigates six cases using data from a Gulf of Mexico deepwater well. The parameters studied include injection rate, injection pressure, shut-in "soak period" time, and volume of injected treatment fluids. The results show that shut-in time, injection pressure, and injection rate are sensitive parameters that can significantly affect tubing movement and wellbore stress on tubulars.
The method of application by means of squeeze treatment or continuous pumping is proven to be an important requirement for these types of operations and should be seriously considered when designing scale-squeeze treatments. These findings also provide the necessary information for optimizing the design treatment, developing good completion spaceout and design, as well as improving operational procedures for scale-remediation applications.
Predicting the Cricondenbar of Lean Natural Gas
Authors: Aimikhe V. J , Joel O. F , Ikiensikimama S. S , Iyuke S 
Published: July 2016

Abstract
This work focuses on predicting lean sweet natural gas cricondenbar. This is an important parameter used in predicting the phase envelope, which determines whether the transported gas is in a single gas phase or a two phase (gas and liquid) and in compressor horsepower sizing and selection. Equations of state are the best methods for predicting natural gas cricondenbar, but they are usually very tedious and rigorous. For instance the use of an equation of state requires the knowledge of the gas critical properties, Acentric factors, Molecular Weight and Binary interaction parameters some of which are not so easy to get. In this study, a FORTRAN compiler was used to generate natural gas composition data in the range of lean and processed natural gas with a specific gravity of 0.58 to 0.69. From the data generated, a correlation was found to exist between the specific gravity of the gas and the cricondenbar. A relationship between natural gas cricondenbar and apparent molecular weight of natural gas was developed. This model was then tested with the calculated cricondenbar of fourteen (14) different natural gases obtained from the field and literature using the SRK equation of state phase envelope utility tool of ASPEN HYSIS software. The results gave a percentage average relative deviation and average absolute deviation of 1.85 and 5.3 respectively.
Predicting Water Content of Sweet Natural Gas – Hydrate Systems
Authors: Aimikhe V. J , Joel O. F , Ikiensikimama S. S , Iyuke S 
Published: July 2016

Abstract
Water content measurement and prediction can be very challenging at conditions of low temperatures and high pressures (hydrate conditions). As a result, many correlations for natural gas water content determination either cannot predict water content of natural gas at these conditions or, have a low accuracy of prediction when they do. In this study, nomographic data generated with the Cubic Plus Association (CPA) equation of state with pressure range of 50 to 500 Bar and temperature range of -20 to 20 °C was used in developing a simple, easy to use correlation with a single predictor (Temperature) variable. This correlation was validated with experimental data obtained from a high pressure variable volume hydrate cell with an analyser based on the Tuneable Diode Laser Absorption Spectroscopy (TDLAS) technology and compared with six (6) other correlations for predicting water content at these conditions. The average absolute deviation (AAD) for the correlations showed that the model in this study had the least AAD of 21 and 5 at 50 and 75 bar respectively. The Behr's correlation had the least AAD of 5 and 10 at 150 and 200 bar respectively, closely followed by the model in this study with AAD's of 9 and 13 respectively. While the Moshfeghian and Sloan correlations gave fairly accurate predictions with maximum AAD's of 36 and 32 respectively, the Kazim and Ning correlations performed poorly with AAD's of 50 and 44 respectively.
Experimental Study of Balanced Activity of Shale During Interaction With Oil Based Mud
Authors: Ndubuisi Elizabeth , O Joel 
Published: July 2016

Abstract
Shales are considered to be the most challenging formation to drill. Over 90% of the formations drilled worldwide are classified as shale formations and about 75% of drilling operation problems are related to shales. There are many factors affecting shale stability, which can be classified into three. The first factors are in relation to geological mechanics, the second type is the chemical factors of the mud which is the main focus of the work and the third type is the engineering factors, which includes the time when the wellbore is opened, the parameters of the depth of the well, inclination and azimuth angles, pressure excitation and drawing. All these factors and parameters governing the shale stability react upon and affect each other, making the problem of wellbore instability extremely complicated. The osmotic effect which is the principal driving mechanism causes water to enter either in the shale or drilling fluid depending on the strength each other. The shale acts like a membrane, but a very poor membrane, so water with improper salt concentration could increase the rate of imbibitions of water into the shale or the reverse may be the case. Therefore, there is need to strike a balance in the design of water activities of the mud and shale in order to achieve wellbore stability. The focus of this research therefore is to design balanced activity drilling mud with the shales from Niger Delta that will prevent wellbore instability. Experimental results for four shale samples collected from the Niger Delta was able to establish the balance activities points for; shale A is 0.86, Shale B is 0.73, shale C is 0.72and shale D is 0.79 respectively. It is recommended that the activities of the shale and oil based mud must strike a balance in order to achieve wellbore stability chemically.
Calculation of Connected Hydrocarbon Initially In-Place Volumes for R5000 Reservoir Using Buckley Leverett & Decline Curve Analysis
Authors: Onu Chukwuemeka , Orekoya Adedoyin , Ori-Jesu Efeoghene , Onita Caroline 
Published: July 2016

Abstract
The use of dynamic method to determine hydrocarbon in-place volumes in R5000 reservoir in Urad field became necessary when it was discovered that the in-place volumes estimated in previous studies for this reservoir cannot be validated by current production data. A combination of Buckley Leverett and Decline Curve Analysis has been used to significantly reduce the wide range of uncertainty reflected in previous in place volumes estimation.
R5000 reservoir in Urad field has two producing wells, one closed-in well and two planned wells; from production data review, it was discovered that estimated in-place volumes was less than optimum. The challenge of re-evaluation to obtain result that both structural interpretation and production performance data will support arose. This paper therefore has deployed Buckley Leverett method with assumption of moderate water drive and gravity drainage to approximate a water flood and as such predict recovery efficiency using the interaction between fluid mobilities, fractional flow and water saturation. Decline curve analysis performed on the producing wells in R5000 reservoir was used to derive technical Ultimate Recovery and a reverse calculation has been done to estimate hydrocarbon initially in-place that supports structure and production data.
The recovery factors of three reservoirs in Urad field, namely P1000, H2000 and K3000 have been previously estimated in an earlier study on this field using Buckley Leverett method and result obtained in this work was validated by repeating the BL evaluation for these three reservoirs to reproduce the recovery factor results obtained in earlier study.
This work provides a solution to the challenge of estimating hydrocarbon initially in-place volumes in reservoirs where available rock and fluid data as well as fluid contacts information are not reliable.
Multivariate Analysis of Air Quality in Selected Oil Operating Areas in the Niger Delta Region of Nigeria
Authors: Ramson Enotoriuwa , Oluchi Nwachukwu Eunice , John Ugbebor 
Published: July 2016

Abstract
This study assessed air quality in selected oil operating areas in Rivers State of Nigeria with consideration to land use type such as oil and gas facilities, major bus stops, schools, Markets, hospitals, residential areas, vegetation and commercial centers. Air quality and meteorological parameters across 25 locations were monitored during the wet season (April to October) 2015 to ascertain major air pollutant sources. The parameters monitored were, Nitrogen dioxide (NO2), Sulphur dioxide (SO2), Carbon ii oxide (CO), Volatile organic compounds (VOCs), particulate matter (PM) 1, PM2.5, PM4, PM7, PM10, TSP, wind speed, humidity and temperature. Descriptive statistics, agglomerative hierarchical cluster analysis (AHCA), Principal component analysis (PCA), Multiple linear regression (MLR) and Principal component regression (PCR) were used in the data analysis and modeling of Air quality index. Results showed that SO2 values ranged from 0.04 ppm to 0.15 ppm, NO2 values ranged from 0.025 ppm to 0.162 ppm, CO concentration ranged from 0.24 ppm to 6.36 ppm, VOC values ranged from 0.18 ppm to 2.19 ppm across all study locations. Particulate matter also varied across the study locations. Three clusters were obtained from AHCA. The dendogram plot from AHCA showed that the observed variation can be attributed to the land use pattern in the study area. Three principal components were extracted from the PCA based on eigenvalue of &gt;1 and from the biplot after varimax rotation revealed that the major sources of air pollution in the area based on land use type are markets, major bus stops, residential and commercial centers. Vehicular emissions, biomass burning and dusty roads are the major sources of air pollution in the study area. MLR performed better than PCR with MLR and PCR having an R2 of 0.967 and 0.930 respectively. PCA, AHCA, MLR and PCR proved to be useful tools in air quality analysis for source apportionment and prediction as this can aid in air pollution abatement planning. There is need to improve existing policies in other to proactively mitigate the impacts of air pollution from oil and non-oil operation sources.
Collaborative Solutions in Well Integrity: Investigating and Restoring Failure of Well Safety Critical Components
Authors: Weaver Sophia 
Published: July 2016

Abstract
A number of SCSSV failures led to deferred production, loss of integrity and additional costs resulting from interventions to restore integrity. An investigation team initially focused on hardware components, until a new multidisciplinary team applied systems thinking to expand the investigation to include operations, subsea controls and fluid components, where analysis on system fluids revealed the root cause – through a series of tests – to be fluid and material incompatibility in the subsea tree hydraulic circuit. Further analysis provided the development of a failure mechanism and understanding of how the problem was exasperated. By executing an integrated investigation, the team gained valuable insight on the fluid and material interactions of the system and was able to make vital recommendations to restore production as well as implement mitigating factors in the approach to completions and well integrity. This paper highlights the collaborative approach to resolving well and subsea integrity between the production, wells and subsea disciplines.
Sustainable Management of Natural Gas Resources: A Case Study of Nigeria
Authors: Okafor Emeka , Carim Akintunde , Onyekonwu Mike 
Published: July 2016

Abstract
There are continued challenges associated with natural gas usage in Nigeria even in the face of both domestic and global increase in its demand. In order to meet those challenges, there is a need for proper management of natural gas resources and its applicable technologies in- Country. In this paper, we highlight the future demand, production and utilization of natural gas based on economic and technological constraints and opportunities in Nigeria with special consideration of its sustainable management. We propose appropriate measures and strategies to meet the challenges associated with natural gas production and usage. We further present results obtained from qualitative evaluation of Nigeria's future gas demand, pricing, and applicable technologies. Overall, the paper provides useful information to decision makers responsible for managing gas resources in a developing Country like Nigeria with commercial quantities of proven gas reserves.