bluuebunny/crossref_metadata_2025_split huggingface dataset:
Variation in the Attitudes of Medical Oncologists Toward Research Biopsies in Patients With Metastatic Breast Cancer
Authors: Seah Davinia S. , Scott Sarah , Guo Hao , Najita Julie , Lederman Ruth , Frank Elizabeth , Sohl Jessica , Stadler Zsofia , Silverman Stuart , Peppercorn Jeffrey , Winer Eric , Come Steve , Lin Nancy U. 
Published: August 2015

Abstract

Background.
Tissue from research biopsies provides access to insights into tumor biology. We aimed to determine medical oncologists’ (MOs’) attitudes toward research biopsies in patients with metastatic breast cancer (MBC).

Materials and Methods.
A total of 309 breast MOs from National Cancer Institute (NCI)-designated cancer centers were invited to complete a self-administered survey about their attitudes toward approaching patients for research purpose-only biopsies (RPOBs), performed as a standalone procedure, or additional biopsies, performed with a clinically indicated biopsy. The MOs were asked to predict what proportion of their MBC patients would consider undergoing research biopsies.

Results.
Of the 309 MOs, 221 (72%) responded. Of these 221 MOs, 30 were ineligible, leaving 191 eligible responders. Nearly all the MOs reported they were comfortable approaching patients regarding research biopsies of blood or skin. One fifth of MOs were uncomfortable approaching patients for RPOBs of the breast. One half of MOs were uncomfortable approaching patients for RPOBs of the liver. A significant variation was found in the perceptions by MOs of their patients’ willingness to undergo research biopsies. The factors associated with increased comfort in approaching patients for research biopsies included fewer years in practice, caring for patients who had undergone recent research biopsies, and the predicted willingness of patients to consent to biopsies. The risk of a biopsy and biopsy-related pain were the most common reasons for reluctance to refer patients for research biopsies.

Conclusion.
Significant variation exists, even at NCI centers, in the comfort level of MOs in approaching MBC patients for research biopsies. MOs’ attitudes toward research biopsies might be a modifiable factor in increasing tissue collection for research.

Implications for Practice:
Tissue-based research is critical in advancing our understanding of cancer biology, and obtaining tissue from a research biopsy provides an essential resource. This study demonstrates the variability of oncologists’ attitudes toward research biopsies and elicits factors associated with increased comfort levels with approaching patients for research biopsies. Biopsy risk and biopsy-related pain were commonly cited reasons not to refer patients for research biopsies. If the risk of a research biopsy is deemed sufficiently low enough to be acceptable, oncologists’ attitudes might be a potential target for education and change, which may assist in increasing the availability of tissue for cancer research.
A Review of Nigerian Bentonitic Clays as Drilling Mud
Authors: Agwu Okorie E. , Okon Anietie N. , Udoh Francis D. 
Published: August 2015

Abstract
The heydays of bentonitic clay production in Nigeria occurred in the late 1950s when oil was first discovered. This was short lived as the advent of imported bentonite took the centre stage in the early 1960s. Since then, there has been no widespread use of the Nigerian bentonitic clay as drilling muds in Nigeria. In the recent past, precisely in 2001, the only major use of Nigerian bentonite for drilling oil wells was made by Shell Petroleum Development Company, Nigeria where over 600 wells were drilled with it. In recent years, Nigerian researchers have been actively pursuing the study of using Nigerian clay as drilling muds and finding potential markets for it. Many of these studies have focused on characterizing and beneficiating the clays to the American Petroleum Institute (API) standard. The available studies in this direction have been chronicled in this paper with the major research findings of each individual researcher brought to the fore. Much of the information that has been gathered in this review indicate that all the researchers were in unison in their submission that the Nigerian bentonitic clay is predominantly Calcium based and that it requires some measure of beneficiation to be effective for use as drilling muds. Mention is also made of possible gray areas where more research efforts should be directed. This work is predicated upon the belief that the works of the past combined with that of the present can lay the necessary framework for future studies on Nigerian bentonitic clays. The review this paper presents can serve as a baseline for the oil and gas E & P companies desirous of unlocking the potential of using Nigerian bentonitic clays as drilling muds.
The Effect Of Wellbore Stability In Naturally Fractured Reservoirs
Authors: Fekete Paul , Bruno Lopez A. , Dosunmu Adewale , Odagme Samuel , Sanusi Adewale , Bowe Ediri 
Published: August 2015

Abstract
Wellbore instability all over the world accounts for a significant in Non-Productive Time (NPT) in well drilling and completions and incurring high cost of drilling as well as increasing safe risks. Real time analysis of data and geomechanics (understanding the rock properties and stresses) has continuously improved the stability of wellbores in the world. Some of the issues cost by this instability are the most common of these losses are: borehole enlargement, cavings, washouts, stuck pipes, deformation of the casing and amongst others.
Numerous wellbore instability problems related to drilling through potentially natural fractured reservoirs/formations have been reported. Most of the this reported formations are been characterized by number of macro and micro scale bedding planes and/or networks of natural fractures which weakens the mechanical strength of the rock and the producibility of potential of the rock matrix. This term paper reviews instabilities issues in Naturally Fractured Reservoirs (NFR), natural fracture reservoir failure mechanism and highlights the effect of instabilities in NFR as well as proper well placement in the NFRs. This paper also looked at wellbore solution in permeable and impermeable formations, borehole failure analyses, drilling strategies to mitigate instabilities in naturally fractured reservoirs and other counter-measures dealing with wellbore instability. The review shows that well design, drilling fluid design, minimizing lateral vibrations of drill pipe and good drilling practices are critical in solving wellbore stabilities in naturally fractured reservoirs.
Local Content Policy and Enterpreneurship: Implications for Small and Medium Scale Industries in the Nigerian Oil and Gas Sector
Authors: Udoh Francis D. , Akpanika Offiong I. , Anietie N. Okon 
Published: August 2015

Abstract
The introduction of the Local Content (LC) policy by the Nigerian Government in the early 2000's was primarily aimed at transforming the petroleum industry into the economic engine room for job creation and national growth through capacity building and empowerment of Nigerian indigenous companies. Through stimulating higher participation of small and medium scale industries and promoting the utilization of local human and material resources in the oil and gas sector, Nigeria was to ultimately develop as the hub for service delivery within the West African sub-region and beyond. The high technology, capital intensive/high risk nature of operations in the oil and gas sector have always been the challenge that militate against the rapid development of successful entrepreneurship and the realization of government's goal in the area. The Nigerian Oil and Gas Industry Content Development Act 2010 has the potential for effective value repositioning, thus raising our small and medium scale enterprises in the sector to reputable service providers capable of wealth creation and contributing to growth of the national Gross Domestic Product (GDP).
Alternative Approachto Multi-Rate Testing
Authors: Obeahon P. P. , Daodu O. , Sedgwick A. , Okereke O. 
Published: August 2015

Abstract
In Nigeria it is a statutory requirement to frequently perform multi-rate test (MRT) on gas wells to update well deliverability and for optimal reservoir management. Analysis of MRT test data provides information on well potential, average reservoir pressure, flow correction, skin factors, condensate and water rate. This information is useful when calibrating well models and in reservoir management. Allthisinformation when not properly estimated can have a huge impact in reserve estimation as well as production forecasting. Traditionally, MRT testing is done using a mobile tester. The inability to conduct MRT tests frequently using themobile tester is due to budget constraints and associated deferment or flaring affectingobligation to meet gas sale agreement. Other demerits associated with the traditional approach to MRT include large personnel exposure, mobilization of heavy equipment, high environmental footprint, inability to flow well to potential due to flare limitation and difficulty in reconciling test rates with actual rates. Due to these limitations, an alternative testing method is proposed. The proposed approach makes frequent MRT's possible and attractive from both economic and HSSE standpoint.
The proposed method discussesusing existing gas central processing facility to conduct MRT. This new method offers a major advantage over the former since it requires little or no equipment mobilization, no flaring nor deferment, reduced number of personnel exposure, no test rate limitation nor rate reconciliation, all of which can be achieved at a significantly lower cost, reduced HSSE exposure and testing duration.
Pilot tests were successfully carried out on well X, well Y & well Z. In each case there were zero incidents, zero deferment and zero production loss. This method saved $2.34M and gained some volume of gas which would have been lost to flaring if testing was done using the traditionalmobile tester. These three pilot examples demonstrate that MRT's can be performed more frequently using an existing gas central processing facility provided all of the metering equipment are installed and that the activities is meticulously planned to capture all of the required data.
Analysis on Traditional Reserve Estimation Methods in Stress-sensitive Gas reservoir: Error Analysis and Modification
Authors: Dou Xiangji , Xinwei Liao , Xiaoliang Zhao , Tianyi Zhao , Zhiming Chen , Weiyan Ren , Rui Zhang 
Published: August 2015

Abstract
Thanks to predecessor's researches, several reserve estimation methods have been proposed over the last few decades, which are commonly accurate for conventional reservoir. However, for stress-sensitive reservoir, permeability is the function of pressure, which may lead to significant errors when using traditional methods even though the flow is boundary-dominated.
In this paper, errors caused by applying several traditional reserve estimation methods based on production data including Flowing Material Balance, Normalized Rate – Cumulative Curved in stress-sensitive reservoir are quantified with numerical simulation. Then, based on the sensitive-analysis, modification procedures for these traditional methods are proposed and validated with synthetic data. Finally, the modified methods are applied to Sulige gas field, a typical stress-sensitive tight gas reservoir.
It can be concluded from the error analysis that for stress-sensitive gas reservoir, Flowing Material Balance and Normalized Rat-Cumulative Curve would result in underestimation. For all the methods above, the magnitude of error is influenced by formation properties, hydraulic fracture qualities, operation conditions and the level of stress-sensitivity. Besides, the error caused by the latter method is larger than that caused by flowing material balance for the same condition. We also find that Flowing Material Balance and Normalized Rate–Cumulative Curve can be modified by introducing new pseudo-pressure and pseudo-time, which take stress-sensitivity into account. These methods are proved to be accurate by both numerical simulated data and field data.
The technique contributions of this paper including: (1) the error caused by stress-sensitivity for traditional reserve estimation methods are quantified and the influencing factors are investigated; (2) modified ideals for traditional methods are proposed.
Coupled 3-D Temperature, Viscosity and Pressure to Investigate the Effect of Heating on Pressure Decline in a Closed Reservoir with high Viscosity
Authors: Akonobea Appiah Elizabeth , Igbokoyi A. O. , Akinojo Omololu 
Published: August 2015

Abstract
Even though heavy oil and bitumen are difficult to produce due to their high viscosity which can be reduced by heating, with increased oil price, the production of these heavy oils are seen viable thus the need for a model that would help make predictions for the future and also take into consideration areal and vertical sweep of hydrocarbons. As a result of a heterogeneity of reservoirs, numerical simulators are used to obtain consistent and significant solutions. For this work, a three-dimensional numerical reservoir simulator is developed for an expansion drive reservoir with a high viscous oil. A transient state heat system by conduction with an internal heat source is considered. A temperature simulator is first developed then coupled with a viscosity correlation after which it is then coupled with a diffusivity equation for a single phase flow of an expansion drive reservoir. All the governing equations are discretized using finite difference technique. Iterative linear solver with the aid of MATLAB code is used to solve the system of linear equations. The study evaluates the performance and the proficiencies of thermal recovery method which is the most common for high viscous oil. The results shows reasonable amount of energy being sustained for more recovery. Without heating, pressure decline is rapid but increasing heat source shows pressure decline being slow.
Empirical Wellhead Pressure-Production Rate Correlations for Niger Delta Oil Wells
Authors: Okon Anietie N. , Udoh Francis D. , Appah Dulu 
Published: August 2015

Abstract
Several correlations have been developed to predict wellhead pressure–production rate relationship in the Niger Delta region. Regrettably, most of these correlations were developed from field data that are not from the Niger Delta region and with limited field test data ranges, so their predictions are lower than expected field values when applied to the Niger Delta. Additionally, some developed wellhead pressure–production rate correlations based on Niger Delta field data are made using in-house equations by the operating companies in the Niger Delta region. To ameliorate this anomaly, sixty four (64) field test data: choke size (S), production rate (q), gas-liquid ratio (GLR), flowing wellhead pressure (Pwh), flowing temperature (FTHP) and basic sediment and water (BS&W) were collected from oil producing wells in the Niger Delta region to develop wellhead pressure–production rate correlations based on Gilbert correlation and modified Gilbert equations. The developed correlations using Niger Delta field test data were compared with several authors' correlations. The results obtained indicate that the developed correlations resulted in better predictions than earlier correlations. In addition, the statistical analysis of the developed correlations used to ascertain the extent of their predicted values differ from the field test data and resulted in average error, absolute error and standard deviation of −0.1477, 0.4430 and 0.9582 for Gilbert formula and −0.2515, 0.4737 and 1.0997 for modified Gilbert formula, respectively. Furthermore, the developed correlations are comparable with an average correlation coefficient of 0.9869. Therefore, the developed correlations can be used as a quick tool to estimate the wellhead pressure–production rate relationship in Niger Delta oil fields.
Evaluation of Cased-Hole Expandable Sand Screen (ESS) Application in Gas Wells.
Authors: Wali Asmau , Uzoho Foster , Nwankwo Cosmas , Ekwealor Jude 
Published: August 2015

Abstract
Sand face completions have a major impact on a well's deliverability, by determining its productivity or injectvity throughout its expected life. In the Niger Delta, most reservoirs are shallow (below 10,000 ftss) and poorly consolidated, sand control forms an important part of sand face completion design. Sand management strategy involves using a software FIST (Fully Integrated Sand Prediction Tool) to carry out sand failure prediction analysis. In cases where sand failure is imminent, a sand control selection guide is used to determine the optimal sand control method to be installed. The selection is benchmarked against the performance of existing sand controls designs in analogue wells the in the region.
A number of sand control mechanisms have been successfully deployed in various completions across Niger Delta which includes Chemical Sand Consolidation, Gravel Packs (Internal/External), Slotted liners, Expandable Sand Screens (ESS), etc. The complexity of deployment varies widely from the most complex multiple IGP/EGP to slotted liners. In all, most of the methods have exhibited good sand control properties however, with varied productivity. The ESS has presented a good balance between ease of deployment, productivity and life cycle management of the well.
A field in the greater Gbaran area of the Niger Delta is proposed to be developed by three gas wells targeting three reservoirs. The reservoirs are unconsolidated and below 10,000 ftss, with Sonic log transit times in the range of 93 - 162 μsec/ft. Sand failure prediction on these three reservoirs using FIST indicated a high failure probability (95 – 100%) during the production life, thus requiring sand control. Following the process of selection, and Cased-Hole ESS was proposed. Although cheaper and easier to install with better productivity, a proper evaluation of the erosion tendency especially in Cased-Hole application of ESS in gas wells is essential to ensure full life cycle coverage.
This paper documents the results of the evaluations carried out, optimization methods employed to evaluate the proposed sand control mechanism.
Thermodynamic Modelling for Mapping Wax Deposition Envelope for an Identified Niger Delta Oilfield
Authors: Johnson-Achilike N. N. , Chukwu G. A. , Ajienka J. 
Published: August 2015

Abstract
Wax deposition is a major concern for the pipeline and oil industry. During normal pipeline and production operations in an oilfield containing waxy crude oil, wax precipitation and deposition will occur which may provide conditions conducive for corrosion to commence. Several Niger Delta oilfields have been identified to contain waxy crude oil. Wax can be deposited in the formation, production tubing, wellhead, surface flow lines and in storage facilities, when favorable conditions of pressure and temperature exist. A decline in the reservoir pressure will lead to a decrease in production rate leading to conditions favorable for wax precipitation and deposition. This becomes a huge concern for marginal oilfields producing at low oil rates. The need to proactively predict the temperature at which wax will precipitate, called Wax Appearance Temperature (WAT), leads to the development and application of thermodynamic models for such predictions. Several models have been developed till date and are currently in use in the Niger Delta but most of them have been validated using data from stock tank oil or dead oil. This makes it unreliable for prediction of wax precipitation during production because the effects of pressure and composition have been neglected. This work aims to modify selected thermodynamic models using live crude oil data from an identified Niger Delta Oilfield with a view to mapping the Wax Deposition Envelope (WDE) which will give an idea of the WAT at different points in the production life of the field.
Regional (Niger Delta) Facie Based Vsh Cut-Off For Net Reservoir Sand Definition
Authors: Anyaehie James 
Published: August 2015

Abstract
Different approaches and methods are used across the various Oil and Gas companies for net sand definition resulting in variation of results even on the same data set. The lack of a consistent, concise and systematic approach in the determination of net sand which is a key input to STOIIP or FGIIP parameters leads to lack of credible and transparent audit trail thereby further increase uncertainties in the hydrocarbon reserves determination.
In general, the common practice is to plot a creaming curve of various Vsh cut off versus equivalent HC column (Porosity * Net sand) and pick the cut off at the asymptote (i.e. at the point where further increase in the value of Vsh used for cut-off has minimal impact on incremental equivalent HC column). Other analytical methods are also used. However, most of this methods, estimate their end points and parameters on aggregate level without consideration for clay distribution within the pore spaces resulting from the genetic variation (facies) within the sand packages, which has significant impact on the storage and transmissibility of the hydrocarbon within the porous media.
This report covers the development of a Niger Delta regional core calibrated faces based Vsh cut-off for the HC resource assessment in absent of actual core for calibration. The research derived various cut-off ranges that covers the major facies observed in the Niger Delta deposition. The developed cut-off values which are calibrated with core acquired within the region are facie specific has greatly simplified and standardize Vsh-cut-off used in estimation of net sand which is a key input in Hydrocarbon resource estimation.