bluuebunny/crossref_metadata_2025_split huggingface dataset:
Detecting Immiscible Flood Fronts in Heterogeneous Systems from Continuous Monitoring of Rate and Pressure
Authors: Jafroodi Nelia , Ershaghi Iraj 
Published: December 2007

Abstract
In this paper, we examine the monitoring of a moving interface problem in immiscible floods in 1-D heterogeneous systems. The solution is presented for monitoring saturation fronts in an extended case of a classical 1-D Buckley Leverette with various lateral permeability profiles. Flood is assumed to be at a constant injection rate but with the opportunity to continuously monitor injection pressure, fractional composition of produced fluid and production pressures. Lateral changes in effective transmissibilities between the injector and the producers caused by movement of immiscible fluid-fluid interface and detected from the solution of interference pressure equation provide an added dimension for tracking the saturation fronts. The effect of the rock heterogeneities is filtered out by analysis of the incremental changes observed with respect to the base measurements at the early stages of the flood.
Evaluation of the Effect of Complex Reservoir Geometries and Completion Practices on Production Analysis
Authors: Cox S. A. , Sutton R. P. , Stoltz R. P. , Barree R. D. , Conway M. W. 
Published: December 2007

Abstract
Complex reservoir geometries can influence the results obtained from transient production decline analysis. For tight gas reservoirs it is common to observe limited drainage areas and linear flow geometries. In some cases these results are inconsistent with the expected geological structural and depositional character of the reservoir. Complex reservoir geometries and flow conditions such as liquid loading can contribute to this phenomenon. Numerical simulation cases will be used to generate the control data sets to demonstrate these effects. This paper will show the effects of complicated reservoir flow conditions on the results obtained from production analysis.
Production analysis is commonly performed in tight gas reservoirs as the analytical technique can be used to quantify reservoir flow capacity, gas in-place, and reservoir geometry (both area and aspect ratio). The results have been used to estimate the effective drainage area, infer completion efficiency and evaluate potential infill drilling spacing for tight gas reservoirs. Complex reservoir cases considered in the paper include stress dependent permeability in both single and dual porosity reservoirs, radial composite systems, and multi-layered reservoirs. From a completion point of view the paper presents the effects of fracture clean-up, fracture damage over time, and the effects of liquid loading on transient production behavior.
Modeling of Equalizer Production System and Smart Well Applications in Full-Field Studies
Authors: Su HoJeen , Dogru Ali H. 
Published: December 2007

Abstract
Equalizer production systems and inflow control devices are used to mitigate water or gas coning problems for mature fields. We have developed new modeling methods to simulate equalizer and interval control valve (ICV) performance in full-field multimillion-cell reservoir models under a parallel computational environment.
We present single-well performance predictions with and without an equalizer, and the results are significantly different in some cases. Full-field modeling with equalizers and ICV controls for several examples has been conducted. In such cases, many individual wells would have significantly improved performance. At full-field level, however, using equalizers or smart well applications without total field optimization would not improve performance much, for reasons we will discuss.
The frictional pressure loss across an equalizer can be considered as a skin, and we have developed an analytical well equation to include it. With this theoretical development, it is now possible to confirm or monitor equalizer performance in terms of pressure drop from pressure transient analysis.
Property Modelling Small Scale Heterogeneity of Carbonate Facies
Authors: Creusen Anouk , Maamari Khalid , Tull Simon , Vahrenkamp Volker , Mookerjee Abhijit , Van Rijen Michiel 
Published: December 2007

Abstract
A heterogeneously complex carbonate reservoir has been characterized texturally and petrophysically at the plug- and core-scale. This rock typing has been used as input to a series of dynamic "mini-models" aimed at correctly deriving static and dynamic rock properties for input into a full field model. Simulation of these mini-models clearly demonstrates the importance of small-scale heterogeneities on hydrocarbon displacement. These small-scale heterogeneities are commonly omitted from standard reservoir modeling workflows.
Sand Clean Out and Acidization of Predrilled Liner Horizontal Hole Sections: A Field Experience
Authors: Ayeni O. L. , Blackall D. , Emeka C. O. , Obadare A. , Uchendu C. 
Published: December 2007

Abstract
This paper describes sand cleanout / acidizing operations of four horizontal pre-drilled liner completions in the UU field, offshore Nigeria. These wells were drilled and completed concurrently with similar completions in 1996. Production from the wells declined after four years. The wells were studied using production history curve analysis and nodal analysis techniques. Analysis indicated that the most probable cause of the decline in productivity was plugging of the completion with solids/deposits.
Detailed analysis and flow testing were carried out on the available core samples from an analogue well to determine the mineralogy of the possible plugging solids and the most effective treatment recipe to be used to remove the plugging materials. Based on the results of the core analysis, sand cleanout /acid stimulation operations were executed on the subject wells, using coil tubing and specialized coil tubing tools.
The operation resulted in a 300% increase in productivity, and was both a technical and economic success.
Equitable Gas Pricing Model
Authors: Ogwo O. U. J. , Mbeledogu I. U. , Nwokedi M. 
Published: December 2007

Abstract
A multi-parameter functional model is generated that would ensure fair gas pricing and minimize subjectivity in the determination of gas prices. Equitable gas pricing would prevent undue price imbalance while ensuring that all stakeholders maximize the benefits of their resources. In the development of this model, various factors are considered ranging from cost of supply and cost of processing (including return on investment) through market availability, gas quality, available fiscal incentives, to market maturity factors. The model (an original analysis on gas pricing) is suitable for determining both short-term and long-term contractual gas prices. A template is presented for evaluating the cost of gas at various supply points. A simulation of gas prices is made using the model, with a given developing gas economy as a test case. The data used for the sensitivity analysis are real data though presented in unclassified form. It is observed that at present the upstream gas of some developing gas economies is not appropriately priced when compared with the cost of production or when reference is taken from the price at the international market.
Optimization of Information/Data Quality Amongst Dispersed Project Teams and Management Groups in the Nigerian Oil and Gas Industry
Authors: Edehe Kufre 
Published: December 2007

Abstract
Recently, Oil and Gas upstream Industries have made tremendous gains in efficiency, productivity and operational performance through the utilization of portal solutions to access their petrotechnical data. This paper provides an insight on the implementation of a complete Data Management Solution aimed at optimizing the quality of data/Information flow amongst project teams and Management groups in the Nigerian Oil and Gas upstream Industries. Data Management anchored on the use of Web portal solutions does not only provide access to various data repositories for modeling, interpretation, simulation, analysis; etc purposes, it helps to improve the operations based on data browsing and access in real time, accelerating the transformation of data to timely decisions thereby increasing productivity and promoting collaboration amongst project teams.
Current geosciences and engineering workflows; ranging from defining data acquisition programs, to building subsurface models, to working up development plans, to actual drilling and productions operations: are relatively disjointed and unstructured. The incoming data required by each of these project teams need to be identified, verified and made available on timely bases. Consequently, web portals tailored to meet E & P needs helps in bringing these data and information to the user's petrotechnical desktop; thus connecting people to data and information.
The scope involved in the implementation of a complete Data Management Solution in one of the Major Oil and Gas Company in Nigeria would be referenced in detail with a view to illustrating how web portal data access solutions has helped in the optimization of the quality of data amongst project teams and Management groups in the Oil and Gas Industry. The importance of this implementation which include and are not limited to the following;
Enhance reservoir recovery production optimization Better Decision made with upfront access to high-quality data Increased efficiency in connecting the field to the office Time wasted in data search is reduced More effort is rather geared into search for Hydrocarbon rather than data Data can be retrieved easily Data update can only be altered through the Web by Database administrator would also be discussed.
Applications of Through Tubing Water Shutoff – SPDC West Experience
Authors: Tope Tunde , Enoto Oton , Kayode Ayeni 
Published: December 2007

Abstract
Water production poses a great challenge in realising maximum value from an oil and gas producing asset. The problems associated with water production include but not limited to early well quitting, resulting in poor oil recovery, restriction of ullage in the surface facilities and huge spend on water handling.
In an attempt to arrest water production downhole, a number of techniques have been successfully deployed. These can be broadly classified as chemical and mechanical water shutoff techniques.
The focus of this paper is on case histories ranging from the conventional mechanical methods to novel chemical water shutoff solutions. The techniques have been applied in completion with diverse complexities ranging from Single String, Short String in a dual completion, Internal Gravel pack, External Gravel Pack to Horizontal well.
The success recorded in most case histories ranges from 100% to about 50% reduction in the original water production while in some cases no success was achieved. Application of these techniques resulted in over US$10 million savings as compared with cost of water shutoff by workover.
Crude Oil Metering Experience in the Niger-Delta
Authors: Iwegbu Michael , Appah Dulu , Ogwo Emma Agu 
Published: December 2007

Abstract
There are increased concerns for improved fluid flow rate measurement by oil & gas producing, processing and distribution companies in order to search for increased flow measurement accuracy and precision.
This work looks at the existing metering procedures and practices of fiscal equipment from custody transfer points of various producing onshore and offshore assets in the Niger Delta region of Nigeria. The work also highlights the sources, magnitudes of these errors and the economic implications of the accruing losses from crude oil metering practices in the Niger Delta.
Results were obtained from field trips, discussions, observations and results of the study showed that usually unity meter factor is applied to meter throughput, meter linearity curves and tables are not established for each meter, optimum or mean K-Factors are used In calculating meter factors. These metering practices ranged from not having appropriate fiscal equipment to not proving meters when required. Significant measurement errors can be further reduced via correction of equipment, procedural and metering problems which would improve metering practices in the Niger Delta region of Nigeria.

Introduction

The Science and Philosophy of Measurement
Measurement is a reference standard used for the quantitative comparison of properties. It is the quantitative and numerical assessment of the dynamic and static properties of naturally occurring phenomena and substances. In the hydrocarbon industry, this is translated to the measurement of fluid flow and static tank gauging. Examples of fluid properties are:Cold (absence of heat) Temperature (T) °F or °C.Mass Volume (V) Cubic Length (cu. ft.- cu. m.).Energy Velocity (S) Length/Time (ft/s. - m/s.).Rate Flow (Q=V/t) Cubic Length/Time (cu. ft./s.-cu m/s.).
Other parameters are pressure, viscosity, density and so on.

Petroleum Measurement
The measurement of the quantity and quality of petroleum and its products, in a liquid or gas phase, has always been important to producers, royalty owners, shippers, transporters, refiners, government agencies and the general public. Measurements are made in connection with custody transfer, inventory control, hydrocarbons movement, and quality determination. Measurements are complicated, so specialized technologies and equipment are developed.
Akpo, Nigeria: From Seismic Interpretation to Geomodel
Authors: Itiola Timothy Oluyemi , Michel Bruno , Bez Martine 
Published: December 2007

Abstract
Akpo is a very light oil to condensate gas field located offshore Niger Delta, discovered end 1999 by Akpo-1 well at a water depth of 1350m, by SAPETRO (operator) - Total TUPNI (technical advisor) and PETROBAS in OPL246.
As for some other turbiditic fields, modelling of the 5 to 20m thick individual channels was the main challenge as they act as the elementary flow units of the reservoir. Although such flow units are under the current available seismic resolution, the developed methodology with object modelling constrained by sedimentological interpretation and seismic derived Vclay cube, allowed to provide reservoir engineers with geologically representative model to be able to simulate properly the flow behaviour and further estimate the reserves.
Reconciling Subsurface Uncertainty with the Appropriate Well Design Using the Mechanical Earth Model (MEM) Approach
Authors: Goodman H. E. , Connolly P. 
Published: December 2007

Abstract
The involvement of the well engineer (WE) competency from the earliest phases of exploration is reaping economic benefit for major capital projects (single wells costing at least $25,000,000 US). As the geological and geophysical modeling work of the Explorationists matures and the subsurface picture becomes clearer, the appropriate well design flexibility is being achieved using Mechanical Earth Model (MEM) technology. This approach to well planning is particularly beneficial for deepwater exploration.
For deepwater subsalt plays, the capital outlays are immense, with single wells costing up to $100,000,000 US. For these projects, MEM technology has been found to be extremely valuable, particularly in characterizing drilling risks associated with well exit points below salt where in-situ stress perturbations can occur. These stress perturbations are being reliably mapped using MEM techniques and the consequences to borehole stability addressed. An example of principal stress rotation gleaned from a deepwater MEM and the consequences to borehole stability is summarized in this paper.
Constructing Inflow Performance Relationship from Surface Measurements: Retreating to the Fundamentals
Authors: Lawal Kazeem A. 
Published: December 2007

Abstract
The Inflow Performance Relationship (IPR) is a key input for integrated studies and optimisation of well/reservoir performance. Constructing the IPR requires reliable flowing bottomhole pressure (FBHP) data. The relatively cheap and evolving option of using flowing tubing head pressure (FTHP) and other surface production data to estimate FBHP depends heavily on a reliable multiphase flow model, as flow in the wellbore is typically multiphasic.
Most of the common multiphase flow correlations relating FBHP and FTHP are empirical, and in spite of their relative complexities, have limited applications. With the conventional modelling approach of assuming an equivalent ‘liquid’ and gas system, these correlations are inherently limited to two-phase flow conditions. In order to honour field data, they often require some form of tuning algorithms, undermining their reliability under situations where such field data are not available.
In this paper, a strictly analytic (mechanistic) four-phase model is presented. The model, hinged on the
basic principles of mass, momentum and energy conservation, accounts for slip between phases, and estimates FBHP from surface measurements, fluid properties, wellbore geometry and completion string data. Its use for IPR construction is also illustrated.
A field example, comparing its performance against an intrinsic two-phase (Beggs and Brill) and an intrinsic four-phase model (Guo), demonstrates its applicability and reliability. Considering its simplicity and robustness, its use can easily be extended to the analysis of drilling hydraulics and other multiphase flow systems that are not explicitly amenable to the so-called generic two-phase approach.
Improved Characterization of Heptanes-Plus Fractions of Light Crudes
Authors: Isehunwa O. S , Falade G. K. 
Published: December 2007

Abstract
Heptanes plus fractions have strong effects on the physical properties and phase behaviour of petroleum fluids. It is therefore very important to properly characterize plus fractions. A step to achieving improved characterization is to obtain more realistic molecular weights. Most of the current methods of heptanes plus characterization assume their molecular weights are accurate. However, what is commonly measured in the laboratory is the molecular weight of the complete fluid; the molecular weight of the heptane-plus fraction is then estimated using Kay's mixing rule. Unfortunately, physical properties like molecular weight obtained using ‘equivalent fluid’ principles by mixing pure components, do not give the same values with actual measurements. Therefore, while a very accurate estimate of the molecular weight of a reservoir oil could be available, that of the heavy fractions, which is ‘inferred’ could be unreliable, because of the mixing rule.
A simple technique has been formulated to achieve improved characterization of petroleum fluids and the heavy fractions. We suggest ‘fine tuning ’ Kay's mixing rule in order to achieve a match between actual measured molecular weight and the ‘equivalent fluid’. Experimental data from over 400 PVT reports from over 100 fields in the Niger Delta were collected and studied. A correlation was established between oil gravity and molecular weight and. compared with other commonly used correlations. Statistical error analysis was undertaken. Heptanes plus molecular weights which were generally estimated using Kay's mixing rule were found to be generally high and hence fine tuned using a simple technique.
The results of this study show that the well-known Cragoe's and Standing correlations gave absolute average deviation of 126.8 and 53.3 respectively for light crudes, compared to 2.5 obtained in this study. Furthermore, better description of heavy fractions was achieved with more accurate molecular weight.
It is concluded that the proposed technique perhaps provides a theoretical basis for the usual ‘tuning’ of heptane-plus properties during fluid modelling. It is also concluded that a more accurate correlation for estimating the molecular weight of light crudes has been developed.
Development and Successful Application of Unique Steerable PDC Bits
Authors: Norris J.A. , Dykstra M.W. , Beuershausen C.C. , Fincher R.W. , Ohanian M.P. 
Published: December 2007

Abstract
This paper describes the development and successful application of unique polycrystalline diamond compact (PDC) bits for use on steerable motor assemblies. The development phase comprised an extensive series of laboratory and field experiments. These showed that proper design of face and gauge aggressiveness were the keys to improved steerability. Notably, the common perception that a short, aggressive gauge is required for steerability was found to be misguided. Field applications from around the world have demonstrated that the new designs minimize tool face fluctuations despite erratic weight on bit (WOB), allow the theoretical build up rate (BUR) to be attained, create superior quality well bores, and provide improved net rates of penetration (ROP) over conventional designs.
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Automation of BOP Bonnet Access: A No Bolts Approach
Authors: Levett B.A. , Brugman J.D. 
Published: December 2007

Abstract
The increased use of drill floor automation has greatly reduced the frequency of accidents involving rig personnel. One area that has yet to benefit from automation safety is the BOP stack. A new BOP bonnet attachment system has enabled automatic opening and closing of BOP bonnets, representing a major step toward automation of BOP servicing. Several operational benefits could be derived from this system both in surface and subsea applications.
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The Implementation of a Computerised Maintenance Management System
Authors: Godot A. , Villard P. , Savournin A. 
Published: December 2007

Abstract
In 1993, after years of using a manual maintenance system based on individual historical cards (T-CARD board), Forasol-Foramer decided to update the system by installing a Computerised Maintenance Management System (CMMS) on all drilling units, the objective being to eliminate the non-productive time.
In accordance with the criteria that the Company highlighted, the Technical Department selected a CMMS software. This program, made up of interconnected modules, can handle all aspects of maintenance, including work order management, preventive maintenance scheduling, history of maintenance done on the equipment, equipment costs, stock control, purchasing and reporting.
In order to adapt the standard product to the Company's specific Preventive Maintenance System, the Technical Department modified the screen presentation and the dialog boxes and created new reports before its implementation on the drilling units. In addition to interface modification, more important was the incorporation of nearly forty years of experience in all the job plan that had to be defined.
The responsabilities and the procedures the users are required to follow have been defined and a user's manual has been created.
A CMMS training course has also been introduced in order to familiarise senior staff to the customised software and to facilitate manoeuvring in the Windows environment for those personnel who are not computer literate.
After 4 years of operational experience, the Company claims that the use of a CMMS leads to an improved system of maintenance, together with an enhanced work reporting indicating precisely which maintenance work has been completed and providing a diminution of non-productive time.