bluuebunny/crossref_metadata_2025_split huggingface dataset:
SE Gobe: Papua New Guinea's Second Oil Development
Authors: Langston M. V. , McCaul T. R. , Fitzmorris R. E. 
Published: December 2007

ABSTRACT
A reservoir development plan was developed from a detailed geological model of the SE Gobe Iagifu reservoir. This model incorporated sequence stratigraphy and extensive core and log analysis to provide the detailed layering framework for reservoir simulation. Cross-sectional balancing techniques were applied to field derived dip and strike, dipmeter log, and RFT data to obtain a structural model for the reservoir. Cross-sectional, sector and, finally, full field reservoir simulation models were constructed and used by the team to generate a reservoir development and management plan.
The simulation models were used to examine the relative merits of vertical, deviated and horizontal wells, well placement, offtake rates, gas compression requirements and pressure maintenance strategies. Due to the uncertainty in the size and shape of the field, development options were considered at each of three reserve levels: proven, probable and possible.
The simulation results showed that well rates should be held to less than 8000 stb/d and that horizontal wells, with a length of at least 700 m, generally out-performed vertical wells. Oil recovery ranged between 34 and 45% of OOIP. The cases offering the best recoveries included both water injection and horizontal wells.
Technology and Economics of Gas Utilisation: Methanol
Authors: Seddon Duncan 
Published: December 2007

ABSTRACT
The paper reviews the current and emerging technology for the conversion of natural gas into methanol and assesses its impact on the production economics. Technologies of potential use for offshore developments of large gas reserves or associated gas are discussed. New technologies for the production of methanol synthesis - gas, such as autothermal reforming and GHR technology, are described and the economic advantages over conventional steam reforming are quantified. New methanol synthesis technology, such as slurry phase reactors, are outlined but appear to offer little advantage over conventional technology for offshore gas utilization.
The purification of methanol for fuel and chemical grade product is outlined and the cost of transport presented.
The data presented gives an overview of the production costs for production of methanol from large gas reserves (&gt; ITcf, 25 - 35PJ/a) and smaller scale reserves (10 - 20MMscfd, 4-10PJ/a). The variation of the production cost of methanol with gas price indicates that the gas price is the principal economic consideration. However, adoption of new technology will improve production economics by an amount equivalent to an incremental gas cost of about $0.5/GJ. For gas reserves of low development cost, the adoption of new technology is not a prerequisite to economic viability.
Maximizing the Value of Multi-Field Developments
Authors: Barker Geoff , Brinschwitz Kurt , Krishnamoorthy Mohan , Mills Graham 
Published: December 2007

Abstract
When a gas or oil field development project consists of a large number of fields using common infrastructure, it becomes difficult to ensure that the development plan chosen for each field will max-imise the value of the total project. The large number of alternative schedules make it impractical to manually evaluate each plan explicitly.
A method based on mixed integer linear programming is presented for maximising the net present value of a gas project consisting of more than 20 fields and prospects over a 40 year time frame. The method estimates the optimum order, timing, installed capacity and offtake profile of each development. The constraints imposed by facilities and sales contracts are incorporated. Phase behaviour and reservoir depletion can also modelled. The paper will present the problem formulation, results of example cases and suggestions for further application and enhancements.
Determination From Well Logs of Porosity and Permeability in a Heterogeneous Reservoir
Authors: Lin Jing Long , Salisch H. A. 
Published: December 2007

ABSTRACT
A technique has been developed for the petrophysical evaluation of well logs from lithologically complex sandstone reservoirs located in the Barrow Sub-basin in Western Australia. The reservoirs are sands of fairly high porosity and low permeability with a significant amount of clay minerals, among them glauconite.
Principal component and cluster analysis were applied to classify the electric fades associated with lithofacies. Bayes discriminant analysis was used to identify several lithofacies in the reservoirs. The different lithofacies are characterised by distinct relationships between porosity and acoustic interval transit times as well as between porosity and permeability. This paper presents mathematical models for each lithofacies for the determination of porosity and permeability from well logs.
Statistical Method To Determine Whether a Wireline Water Sample Is 100% Mud Filtrate
Authors: Remeljej C. W. 
Published: December 2007

ABSTRACT
Formation fluid samples are frequently obtained by twin chamber wireline sampling or less commonly by pump out sampling tools. If a retrieved sample is found to be practicably 100% water (negligible hydrocarbons) the immediate question is whether the sample is filtrate (water based mud used) or contains a significant proportion of formation water.
This paper details a novel statistical approach which applies ANOVA (One Way Analysis of Variance) to assess whether a water sample is pure filtrate or has been diluted with formation water. This qualitative information assists in the decision to further evaluate the formation with the wireline sampling tool. This method requires only the analysis of some non-reactive or marginally reactive ions in the mud system.
No specific tracer, such as tritium, is required for this method.
Quantifying HIRES Nuclear Tool Resolution in Thinly Bedded Reservoirs Using Time Series Analysis
Authors: Dodge W. S. 
Published: December 2007

ABSTRACT
To assess the benefits of high resolution nuclear logs run in the Gippsland Basin, time series analysis has been used to quantify vertical resolution and random noise. Time series analysis involved taking the Fourier transform of the measurement signal which was then analysed in the frequency domain. The frequency response characteristics of the signal were used to compute the vertical resolution of the measurement based upon signal and noise coherence. The signal to noise ratio of the measurements yielded information about the random broadband noise inherent in nuclear measurements.
HIRES data provided by service companies showed a significant vertical resolution enhancement relative to standard acquisition data but at the expense of greater random noise. The enhanced resolution processing algorithms used by one service company improved the intrinsic resolution of HIRES bulk density and thermal neutron porosity data, while the other company's processing showed enhancement for the bulk density measurement but not the thermal neutron porosity. Broadband noise is a significant tradeoff to using data with enhanced resolution processing for both the bulk density and neutron porosity measurements.
The Influence of Fluid Properties on the Success of Hydraulic Fracturing Operations
Authors: Power D. J. , Paterson Lincoln , Boger D. V. 
Published: December 2007

ABSTRACT
HydroxyprOpylguar based fluids are the most commonly used fluids for hydraulic fracturing. Through the addition of borate ions the polymer present in the fluid can crosslink to form a high viscosity gel. Prior to placement in the fracture the fluid is required to have a low viscosity to minimise friction losses in the tubular goods. A high viscosity fluid is required in the fracture for several reasons, primarily to suspend the proppant and to minimise fluid loss into the formation.
This paper describes a new method which can be used to model the gelation reaction of crosslinking fluids. By modelling the dynamic properties of the fluid it is possible to predict the physical state of the fluid at any time during a fracturing treatment. Small amplitude oscillatory measurements are applied to fluid samples in a cone-and-plate geometry. The change in the dynamic properties with time can be fitted to a simple model which can then be used to determine the gel time for th6 fluid. Methods used to distinguish between the liquid and gel state are also discussed.
A State-of-the-Art Production Information Management System: Conception to Completion
Authors: Parker A. R. , Corston S. P. , Abdallah F. F. 
Published: December 2007

Abstract
The task of hydrocarbon production accounting for oil and gas development projects can be extremely complex and time consuming, especially if Joint Venture Partner (JVP) ownership varies over several inter-related producing projects. For this task to be carried out quickly and accurately a diverse range of computer software and hardware is usually employed. This paper explains the planning, specifications and construction of an online Management Information System for hydrocarbon production balancing, reconciliation and reporting over the North West Shelf Gas Project.
Carbon Dioxide Foam Flood Studies Under Australian Reservoir Conditions
Authors: Tortopidis Sofie , Tortopidis D. C. 
Published: December 2007

ABSTRACT
Carbon dioxide flood sweep efficiency may be enhanced by the use of foam-forming surfactants.This paper describes an experimental program conducted to study the potential of foams to enhance oil recovery within Australian reservoirs. Laboratory bench-top scale equipment was used to simulate such conditions. Initial tests to determine the foam-forming ability of seven different surfactants were conducted in a one-dimensional quartz sand packwith no oil present. Further experiments were conducted on three of the surfactants in the presence of a light crude oil. Subsequently tests were performed in a simulated reservoir construction made of the sands taken from an actual Australian reservoir. A surfactant has been identified that generates a stable foam under the conditions that exist within an Australian petroleum reservoir.
From Disposal at Sea to Distribution of Oil-Based Cuttings
Authors: Bohm J. T. C. , Laan L. v. d. 
Published: December 2007

ABSTRACT
The environmental impact of cutting discharges has led to a significant change in the way oilbased mud has been used at the Dutch Continental Shelf (DCS). The industry has converted from direct disposal of oilbased cuttings to a zero oil disposal at sea by transfer of cuttings to land. Moreover, distillation of cuttings has resulted in a closed-loop application of the base oil. This method has been developed as a standard operation even before the zero oil disposal limit became effective in 1993. Although the well costs have increased with 2.5 % as a result of the new requirement, the extra costs amount to only a small fraction of the extra well costs if only waterbased mud would be allowed. Both industry and environment benefit and it has resulted in an increased use of oilbased mud since 1991 at the DCS. Further scope for reduction of environmental impact related to waste disposal is limited. The remaining concerns are related to the prevention of oil spills.
Water-Based Glycol Drilling Muds: Shale Inhibition Mechanisms
Authors: Aston M. S. , Elliott G. P. 
Published: December 2007

ABSTRACT
Water based glycol (polyol) muds are becoming increasingly popular, and are now replacing oil based muds in many drilling operations. Apart from exceptional shale inhibition, other benefits include environmental friendliness, ease of handling, robustness and good lubricity.
This paper explores the mechanisms of shale stabilisation by glycol muds. Experimental data show shale dispersion, swelling and hardness behaviours for a model reactive shale (London Clay). The data suggest the high level of inhibition obtained is mainly due to a shale hardening effect - the shale actually becomes harder than in its original state. Measurements with a range of salt types show that salt (eg KC1) plays a major role in the inhibiting mechanism.
Adsorption measurements indicate that the glycol displaces water from the shale, resulting in a change in pore fluid composition. In effect, the glycol acts as a penetrating glue which, it is believed through hydrogen bonding effects, strengthens the shale. This mechanism contrasts with other water based mud additives (e.g. PHPA or polyamines) which form a protective or encapsulating layer on the surface of the shale.
The Formulation of Milling Fluids for Efficient Hole Cleaning: An Experimental Investigation
Authors: Ford J. T. , Oyeneyin M. B. , Gao Erhu , Williamson R. S. , Peel L. C. 
Published: December 2007

ABSTRACT
This paper describes a set of experiments, sponsored by Mobil North Sea Ltd (MNSL) and conducted at Heriot-Watt University, which were designed to investigate the carrying capacity of milling fluids. The objective of this work was to determine the fluid rheology which would most efficiently transport debris (swarf), generated during casing milling operations, out of the hole. The results of the experiments and subsequent analyses are presented in the paper.
The paper describes the equipment and procedures used in the experiments. It also presents the results of the experiments and subsequent analysis relating to the transport efficiency of a range of milling fluids used by MNSL. These experiments were conducted under static and dynamic conditions using a recently constructed settling column and the cuttings transport borehole simulator at Heriot-Watt University. The experiments demonstrate the impact of the rheological properties of the fluid, and the shape and surface area of swarf on transport efficiency. The paper concludes with recommendations on the formulation of fluids for milling operations of this type.
Well Test Interpretation in a Heterogeneous Braided Fluvial Reservoir
Authors: Toro-Rivera M. L. E. , Corbett P. W. M. , Stewart George 
Published: December 2007

ABSTRACT
Braided fluvial reservoirs are important reservoirs around the world and being high net: gross, are often considered to be massive and relatively easy to characterise. This study shows that this is not always the case. Two wells in the offshore part of the fluvial Triassic Sherwood Sandstone reservoir in the Wytch Farm Field, Southern UK, have very similar permeability distributions with arithmetic average permeabilities of 400 and 625md, respectively. The effective permeabilities exhibit a similar and typical degree of heterogeneity in this fluvial reservoir in terms of core permeability. However, their well test effective permeabilities are radically different (44 and 1024md).
A full well test analysis is performed for each well, deriving all possible models that can be interpreted from the pressure derivative. The well testing software used (PanSystem™) allows filtration and resampling of the pressure data and the interpretation of the pressure derivative curve and identification of early, middle and late time flow regions. The models interpreted from the well test analysis are integrated with flow unit models derived from the core permeability, core sedimentology logs and knowledge of the reservoir geology. The flow unit interpretation can be directly related to the well test results. The spatial distribution of the permeabilities is different in the wells and this explains why the probability distribution functions alone fail to discriminate between the wells.
This work addresses the challenge of estimating effective permeabilities in high net:gross braided stream reservoirs. Permeability in this particular field varies by seven orders of magnitude and there is high grain size derived variability at the core plug scale. Interpretation of the well test in such environments can be greatly helped by an improved petrophysical description (probe permeameter), careful screening and averaging of the core data and identifying the flow units (which may differ from conventional net pay). In addition, we observe that the occurrence of negative skin in such environments can be attributed to natural simulation due to sedimentological features. We point out that the running of a production log (PLT) during the testing will greatly reduce the uncertainty in flowing interval and the test-derived parameters.
This work shows that the integrated interpretation of well test pressure data in a geologically-coherent fashion can enable the flow characteristics of the reservoir to be determined at the appraisal stage. This knowledge can then be incorporated in the model of the reservoir for improved performance prediction.
Rate-Dependent Skin From Afterflow
Authors: Lingen P. L. 
Published: December 2007

SUMMARY
During the afterflow of a pressure build up in a gas well test a unique pressure response is created by the declining rate dependent skin. This paper describes a method to include the effect of the declining rate dependent skin in the response of analytical well models. This results not only in an improved analysis by regression, but also in the possibility to obtain the rate dependent skin from the afterflow response of a single rate gas well test with build up. The accuracy of the resulting rate dependent ~kin values has been validated in some ten multi-rate test analyses.
IOR Potential with Updip Water Injection in the Statfjord Fm at the Statfjord Field
Authors: Hegro Einar , Dalen Vilgeir , Strandenaes H. O. 
Published: December 2007

ABSTRACT
An element model was used to investigate the effect of using the existing crestal gas injectors in the Statfjord Fm at the Statfjord Field for additional updip water injection. The element was extracted from a history matched full field model and refined. The simulations gave accelerated production and increased oil recovery of approximately 5% with updip water injection, primarily because of better pressure maintenance, better sweep of lower parts of the formation and less problems with gas production constraints. Sensitivities on selected parameters did not indicate anything in disfavour of updip water injection. Full field simulations have confirmed the potential of updip water injection, and the scheme is found to fit very well into the overall Statfjord Field strategy.
Productivity of Multifractured Horizontal Wells
Authors: Hegre T. M. , Larsen Leif 
Published: December 2007

Abstract
Accurate methods are presented to determine the productivity of multifractured horizontal wells with transverse or longitudinal fractures. Charts combined with a simple expression give the relationship between the effective wellbore radius and fracture conductivity, fracture size, wellbore radius, number of fractures and distance between the fractures as dimensionless parameters.
The effectiveness of multifractured horizontal wells is illustrated by a variety of examples, with well response compared to non-fractured vertical and horizontal wells and to fractured vertical wells. It was identified that stimulating horizontal wells is favourable in thick formations and in reservoirs with low vertical to horizontal permeability ratio. In particular, it is shown that the potential productivity of horizontal wells stimulated by transverse fractures is higher than for wells stimulated by longitudinal fractures. However, a low fracture conductivity has a much more adverse effect on transverse fractures compared longitudinal fractures. The importance of the number of fractures and especially the distance between the fractures also is demonstrated. Some existing analytical solutions are also discussed and comparisons are made with results from this paper.
Parametric Study of Gas-Condensate Reservoir Behavior During Depletion: A Guide for Development Planning
Authors: Bourbiaux B. J. 
Published: December 2007

ABSTRACT
The results of systematic compositional simulations of gas- condensate depletion in a radial and cross-sectional reservoir model are presented. The effects on productivity, recoveries and fluid distribution are analyzed and quantified when changing various parameters, such as the role of non-Darcy flow, the permeability, the relative permeabilities (kr) in relation with the interfacial tension (IFT), the nature of the fluid.
Below the dew point pressure, the drop in gas productivity is linked to the development of a condensate ring around the wellbore. Gas and condensate kr and their dependence on IFT control the time or pressure at which condensate buildup becomes significant and gas productivity drops. Tight reservoirs with lean gas-condensates may pose early and drastic productivity problems. Far from wellbore, condensate may segregate under the low-IFT conditions met during depletion, especially if the reservoir permeability is high ana the fluid is rich. In a depletion process, condensate recovery is all the lower as the condensate content of the fluid is higher.
The results of this study can be used as a guide during the development planning of a gas-condensate field (1) to estimate the quantitative role played by key rock-fluid parameters during future exploitation, (2) to define the most relevant corefluid measurements and simulation studies for reducing uncertainties on field performance predictions.
Improving Profitability of Gas and Oilfield Operations by Applying New Technologies
Authors: Hartmann Ulrich , Muessig Siegfried 
Published: December 2007

Summary
Gas fields at an advanced stage of depletion require measures to overcome the back pressure of the gas transmission system and thus maintain production rates. This paper describes measures for cutting costs by applying either conventional or new technologies such as on-site conversion of natural gas into electrical power by combined-cycle processes or fuel cells.
A Fitted for Purpose Slim-Hole Rig
Authors: Sagot André , Dupuis Dominique 
Published: December 2007

ABSTRACT
After testing new slim hole drill strings that are able to perform destructive drilling and wireline coring with positive drilling achievement and positive geological data acquisition, the construction of a purpose built rig for slim hole drilling has been undertaken. It is believed that a purpose built rig will lead to substantial drilling cost breakthroughs and greatly reduce the environmental impact of the drilling operation.

Reducing the Drilling Cost

Environmental protection

Slim Hole Prilling Practices
Slim hole drilling requires a refined control and measurement of all drilling parameters. To achieve this, we need:
Slim hole drilling requires a new rrange of flow parameters versus conventional practices. An original solution has been developed and is presented in this paper.
Based on the above criteria the paper will detail the solutions that provide the foundations adopted to build the slim hole purpose built rig. The rig has begun operations in France in April 1994. The initial results will be available.