bluuebunny/crossref_metadata_2025_split huggingface dataset:
Realizing True Value From Rotary Steerable Drilling Systems
Authors: Johnstone John A , Allan Derek 
Published: December 2007

Abstract
To date the main focus in the use of Rotary Closed Loop System (RCLS) drilling technology has been the cost savings associated with the increase in the gross rate of penetration that can be achieved. This ignores the other value drivers, for example, improved real-time reservoir navigation and optimal placement of the well bore in the reservoir. This paper will demonstrate and quantify the benefits that can be realized in the use of this technology. Furthermore, it will demonstrate the increased flexibility that exists in the directional planning and execution of the well.
Field data shows how drilling performance on complex 3-D well trajectories, including horizontal and extended reach wells can be improved, and how the effects of common well bore problems such as spiraling, ledging, cuttings bed build up and formation damage can be minimized. The examples given a) demonstrate the performance improvements achieved and b) show further benefits in the reduction of problems associated with running the completion string through the delivery of a competent and useable well bore. A financial analysis taken from an operator case study clearly demonstrates the potential return on investment in RCLS technology.
Innovative rotary closed loop drilling can be used to extend the life of a field, particularly in a mature asset within the constraints of existing infrastructure. It has significant potential to reduce the number of wells required with existing technology to efficiently exploit the reservoir, clearly demonstrating the value it can bring to the operator.
Cement Plugs: Stability and Failure by Buoyancy-Driven Mechanism
Authors: Crawshaw J. P. , Frigaard I. 
Published: December 2007

Abstract
Setting cement plugs off bottom is a well recognised problem in the industry. Different causes of failure have been identified over the years and many have been addressed by improving practices used in the field. A remaining problem is the instability of the lower interface between the cement and the fluid below, driven by the greater density of the cement. That is, once a cement plug has been injected into the wellbore it must resist the tendency to fall through the less dense drilling fluid below until the cement has set. The fluid properties which ensure stability have never been satisfactorily established and it is this gap which is addressed by the current work.
Theoretical and experiment results are presented in this paper which allow the estimation of the yield stresses required of the fluids to stabilise a cement plug under any conditions of hole size, inclination and density difference between the cement and the fluid underneath. The experimental work shows that the model is somewhat conservative and this is discussed in terms of the assumptions made in each case.
Drilling Mud Discharge Reduction in the Shearwater HP/HT Gas-Condensate Field
Authors: Darke K. E. , Browning G. 
Published: December 2007

Abstract
British Government legislation effectively prohibits the offshore disposal of oil contaminated cuttings. By the end of 2000 this will include cuttings contaminated by synthetic / pseudo-oil based muds. In high pressure and temperature environments such as Shearwater, temperature and wellbore stability constraints restrict the use of existing silicate water based muds to tophole sections. Total containment of cuttings is therefore required. The Ship and Skip program implemented on Shearwater has demonstrated that total cuttings containment is possible even during high speed drilling of larger hole (16") sections without incurring drilling downtime. The phased nature and sound planning of the program was key to operational safety and cost.
Partnership, to Improve Health and Safety
Authors: Spiller Roger , Buirds Bobby 
Published: December 2007

Abstract
The UK oil and gas sector is becoming mature at a time of reduced oil prices and higher costs. Cost reductions coinciding with an increase in serious injuries require a new approach to health and safety.
The traditional anti union focus of the industry is now changing giving the Trade Unions an opportunity of working in partnership with oil companies and contractors to maintain an efficient and profitable industry whilst securing high standards of safety and employment conditions. The inclusion of Trade Union Safety Representatives will benefit the improvements needed.
Management of Occupational Health Offshore: Still a Challenge for the Industry?
Authors: Gardner R. J. , Wiig H. 
Published: December 2007

Abstract
Although little is known about the costs of work-related ill-health in the offshore sector, experience elsewhere suggests that these could be considerable. Yet occupational health has been recognized as a "poor relation" offshore compared with safety. The various reasons for this are discussed. An important feature is that data is needed in a form which not only convinces management of the need to take occupational health issues more seriously, but also allows them to develop performance indicators to measure how well they are doing. The available information and data suggests that musculoskeletal disorders and dermatitis are of particular concern offshore. Also the potential for problems from noise induced hearing loss and vibration white finger are high. Some areas of the management of prevention of work-related ill-health offshore which need attention are discussed and some performance indicators against which success may be measured are suggested.
Mapping Reservoir Saturation with Seismic Resolution to Improve Reservoir Model
Authors: Reymond S. B. , Soenneland L. , Strudley A. 
Published: December 2007

Abstract
Improved oil recovery on mature fields relies on a reservoir model accurate enough to identify by-passed oil and to monitor fluid responses to production. Integration of seismic 3D volumes with stochastic realisations and flow simulations in a single interpretation environment (Shared Earth Model) allows asset teams to perform rapid seamless iterations leading to a perfected representation of the reservoir (Fig. 1). Facies, fault and fluid mapping from 3D/4D/4C seismic data has moved one large step ahead with the advent of grid-based and 3D volume seismic classification (Fig. 2). Resulting deterministic spatial probability estimates of reservoir parameters are direct inputs to the reservoir model to constrain large uncertainties present in geostatistical distribution of reservoir parameters.
Seismically Guided Bypassed Oil Identification in A Mature Steamflood Area, Duri Field, Sumatra, Indonesia
Authors: Sigit R. , Satriana D. , Peifer J. P. , Linawati A. 
Published: December 2007

Abstract
The first large project area under steamflood at Duri field, Area 1, has recently been ramped down to the maintenance steam injection rate. After 14 years of steaming, Area 1 has achieved a recovery factor of about 64%. The available generated steam for this area, aside from the maintenance steam, is now being used to initiate new area development.
In 1996, the first 3D seismic survey in this area was acquired in the Southwest portion of Area 1 covering 33 patterns. This 3D seismic survey was aimed as a pilot project to identify the potential bypassed oil. The presence of the steam in the reservoir has changed the seismic velocity, distorted the seismic energy and lowered the frequency content. These factors have therefore lowered the seismic resolution to be able to resolve every injected flow unit. Vertical seismic profiles (VSP) have been heavily utilized as control data to interpret the flow unit boundaries and the faults. As a result, two major flow units (Pertama and Kedua-Baji Jaga units) were interpreted with confidence. Seismic attributes were extracted from these flow units. Pore fluid characterization was done using multi-variate statistical technique from the extracted seismic attributes to obtain the most reasonable steam saturation and bypassed oil maps which match the engineering data and production history. It was found that the bypassed oil regions were mostly controlled by both the stratigraphic and faulting systems.
A re-development strategy was generated by a multi functional team to recover the remaining oil. Seismic data was used to guide the interpretation of bypassed oil in areas not immediately adjacent to observation wells. This strategy consists of:
Selective zone re-injection Pattern re-alignment including well conversion and infill injectors Infill vertical and horizontal producer wells.
A target of about 4.6 MMBO of bypassed oil was identified in the study area. The approach used in this study has potential application in other areas in the Duri field that are in the earlier stages of the steamflood process. This would enable to recover of the oil as early as possible in the potential bypassed regions.
A New Numerically Model of Single Well Radial Multiphase Flow In Naturally Fracture Reservoir System, Using Fractal Concept
Authors: Dyah Rini R , Kana J. C. , Abdassah Doddy , Mucharam Leksono , Sucahyo W. P. 
Published: December 2007

Abstract
A new numerical simulation of single well reservoir model with fractal concept has been successfully developed in this study. The mathematical equations in which fractal dimension is explicity included have been formulated numerically for the radial three-phase flow (oil, gas and water) using a cylindrical coordinate system. By these new formulations, a radial multiphase flow in naturally fracture reservoir was modeled by assuming that all storage capacity in the rock system is merely due to fractures. The formulations of this model were then solved numerically by implementing the IMPES solution technique.
The model developed had been validated with the analytical model of single phase flow in radial system developed by Aprilian (SPE # 26465, 1993). In all cases, comparisons of these two models had shown similar results.
Using this new model, reservoir performance prediction of single well reservoir models had been performed with various cases and fractal dimensions. In this particular cases, the resulting performances of several hypothetical reservoirs with various fractal dimensions were then correlated to generate new type curve models. These type curves can be used for estimating fractal dimension of a reservoir.
A New Method for Designing 3D Trajectory in Sidetracking Horizontal Wells Under Multi-constraints
Authors: Shengzong Jiang , Xilu Wang , Limin Cao , Kunfang Liu 
Published: December 2007

Abstract
This paper proposes a new method for designing 3D trajectory in sidetracking horizontal wells based on optimization theories, in which some factors such as kickoff point, performances of bent housing motors, and tool-face angles etc. are considered quantitatively. The validation of this method is shown by more than 10 case histories. Comparison with conventional methods, the new method can greatly simplify the design process, generate more smooth curves with less length and can hit the predetermined point or target with higher accuracy.
New Experimental Approaches in Minimum Miscibility Pressure (MMP) Determination
Authors: Kechut Nor Idah , Zain Zahidah Md. , Ahmad Noraini , Ibrahim DM Anwar Raja DM 
Published: December 2007

Abstract
Miscible CO2 gas injection has nowadays become one of the most important enhanced oil recovery (EOR) processes. For optimal displacement efficiency, CO2 flooding should be conducted at pressures greater than a minimum miscibility pressure (MMP), which is a function of temperature and composition of injection gas. The MMP has been defined as the minimum pressure at which the injected gas and the oil become miscible with each other. Approaching miscibility, the interfacial tension (IFT) between phases decreases resulting in decreased residual oil saturation, hence, higher oil recovery efficiency.
This paper presents two new experimental approaches to determine the MMP for the miscible CO2 gas injection. The first approach consists of measuring the interfacial tension (IFT) between the injected gas and the oil at reservoir temperature and varying pressures using a prototype Vapour Liquid Equilibrium-Interfacial Tension (VLE-IT) equipment. The miscibility of the injected gas and the oil is evaluated on the basis of the vanishing IFT between the two phases.
The second experimental approach involves the MMP determination by displacement test using a prototype Gas Extraction & Miscibility Analyser (GEMA)*. The invention incorporates a capillary-sized unpacked column or a micro-slim tube (MST) as opposed to the conventional packed slim-tube widely reported in literature. The MMP analysis time reduces up to one tenth of the conventional slim tube or sand-pack flood.
It is demonstrated in this study that the approaches are reliable and fast for determining CO2 MMPs. The IFT method yields the quantitative information and the IFT MMP obtained is verified by the micro-slim tube displacement tests. The MMP obtained also falls within the range of values predicted by published correlations.
Petrophysical Properties of Sandstones Under True Triaxial Stresses I: Directional Transport Characteristics and Pore Volume Change
Authors: Al-Harthy S. S. , Jing X. D. , Marsden J. R. , Dennis J. W. 
Published: December 2007

Abstract
Transport properties are important parameters in controlling reservoir performance, and an understanding of how fluids flow through a reservoir can aid successful management of hydrocarbon recovery. Traditional laboratory measurements of permeability and resistivity are carried out in one direction which does not take into account any anisotropy in the rock properties. Furthermore, laboratory measurements of these properties are often carried out under conditions of equivalent hydrostatic stress, or sometimes anisotropic triaxial loading in which two of the principal stresses are equal. However, permeability and resistivity may vary in the three principal directions, and pore volume change may differ under different stress paths.
A novel method for measuring directional permeability and resistivity on a cubic sample under realistic true triaxial stresses has been developed and used in this study. This paper presents laboratory measurements of directional permeability, directional resistivity and pore volume change under conditions of hydrostatic and true triaxial stresses. Measurements of permeability and resistivity were carried out in the three principal directions using cubic rock samples of outcrop and reservoir sandstones. The main objectives of the work was to investigate directional and stress dependence of transport properties under realistic true triaxial stresses.
Results have shown greater pore volume change to occur under comparable hydrostatic compared to true triaxial stresses. The samples with laminations showed high degrees of anisotropy in permeability and resistivity under conditions of hydrostatic and true triaxial stresses. The degree of anisotropy was found to be constant between low and high stress. The permeability values were found to be higher under true triaxial stresses than under their corresponding equivalent hydrostatic stresses, whilst resistivity showed little differences. Thus the results have shown the importance of measuring directional transport properties and pore volume changes under realistic stress conditions.
New Air Injection Technology for IOR Operations in Light and Heavy Oil Reservoirs
Authors: Greaves M. , Ren S. R. , Xia T. X. 
Published: December 2007

Abstract
A new air injection technique, low temperature oxidation (LTO) process for residual light oil recovery, is described. Improved oil recovery from deep, light oil reservoirs is achieved by removing the oxygen in the injected air by LTO reactions with the residual oil in the reservoir. The product of the LTO reactions is a "flue gas", which displaces the oil. Preliminary results of LTO reaction kinetics and oil recovery have been obtained using four North Sea light oils.
THAI - "Toe-to-Heel" Air Injection, is a new EOR process, which integrates advanced reservoir technology and horizontal well concepts, to achieve potentially very high recovery of heavy oil. It can also realise very substantial in situ upgrading by thermal cracking, producing upgraded oil to the surface. The process operates in a gravity stabilised manner by restricting drainage to a narrow mobile zone. This causes the flow of mobilised fluids to enter directly into the exposed section of a horizontal production well. The process can be operated on primary production, as a new technology, as a follow-up to existing technologies, or as a co-process where the advantages of high thermal efficiency are required. This is achieved by concentrating the energy required for oil mobilisation, recovery and thermal upgrading in the reservoir.
Combined with clean technology design, THAI offers a pathway to future economic success for the heavy oil industry.
Enhance Oil Production in High Waxy Oil Reservoir by Single Well Cyclic Microbial Injection-Production
Authors: Chen Wei , Miao Mingcai , Chen Ling , Wan Dexin 
Published: December 2007

Abstract
The Sha 3 reservoir of Zhuangxi oil field is characterized by low permeabilityjhigh waxy oil and high reservoir temperature (92~115°C). The wax content of the crude oil is 18~46%, and its your point reaches 21~53 °C. Wax deposition results in various troubles, so that the producers can not work continuously, and the oil production and oil recovery is very low. In order to improve the oil recovery, the cyclic microbial injection-production testing was conducted in 10 wells. Two kinds of microbe were used. One is for controlling the wax, and the other is for treating the gum and bitumen. The preliminary result is satisfactory. Observation includes reduction of wax content and pour point and increment of oil production and light components of the crude oil. As a result, the power consumption and troubles decreased obviously. This paper introduces the well selection.field tests, observations and the results.
Hysteresis in Dielectric Properties of Fluid-Saturated Porous Media
Authors: Nguyen Buu-Long , Bruining Johannes , Slob Evert C. 
Published: December 2007

Abstract
We present in this paper the results of measurements of the complex dielectric permittivity and electric conductivity in three different porous media, made from unconsolidated acid-purified quartz sand and glass grains. To ensure the generality of the results, we use sand and glass grains of different geometry and particle size distribution. The measurements are made in the frequency range of 300kHz-3GHz, which covers the operating frequencies of all electromagnetic tools.
We have made measurements in a specially designed capillary pressure cell with a built-in transmission line which goes through the porous media. The measured capillary pressure curves serve as an indication of the capillary hysteresis during the entire drainage and imbibition cycle. From the scattering characteristics of the built-in transmission line, we computed the complex dielectric permittivity of the porous media as function of frequency and water saturation.
We obtained different values of complex dielectric permittivity and electric conductivity at the same water saturation during drainage and imbibition. At water saturation lower than approx. 0.6 the values of permittivity for the imbibition is lower than those for the drainage. At higher water saturation, the picture is the other way around.
Well Test Analysis for Multiphase Displacement Reservoir
Authors: Yin Hongjun , Zhai Yunfang , Fu Chunquan , Ma Shuilong , Li Zhongchen 
Published: December 2007

Abstract
In tertiary-recovery projects, kinds of measure are adopted to enhance oil recovery. One of them is alternate gas and water injection. After this measure, the displacement fluid in the reservoir becomes a gas-liquid mixture. Well test analysis for such multiphase displacement reservoir is still difficult.
In this paper, a mathematical model of the composite reservoir is established. The dimensionless wellbore pressure drop is solved analytically by using the Laplace transformation with numerical inversion. The corresponding type curves for appropriating injection/producing well are given. Moreover, the numerical solution is obtained by numerical simulation that considers effect of saturation distribution. By combining numerical method with analytical method, the inner and outer region mobility, skin factor, wellbore storage constant and front radius can be determined. Together with field examples, the paper analyzes pressure transient data of injection well and producing well.
Selected Indonesian Microbes Potentials For MEOR
Authors: Kadarwati Sri , Udiharto M. , Hadi Noegroho , Doria Indria 
Published: December 2007

Abstract
Oil recovery can be increased through the activities of microbes in a process known as Microbial Enhanced Oil Recovery (MEOR). MEOR technology has been implemented in a number of oil producing companies and has proven to have good prospect, environmental friendly and low cost.
The microbes which proliferate in Indonesia oil fields should be subjected to laboratory identification. Samples of formation water, oil, and soil were taken from various oil fields. These oil fields were selected on account of their reservoir temperatures which promise optimum growth of microbes. In order that MEOR can be applied in these oil fields, the microbes existing in their oil wells were isolated and identified.
Based on the results of isolation and identification activities several indigenous bacteria species were obtained from the oil well environment. The potential of each bacteria species for use in MEOR process depends on their ability to live and grow in the reservoir environment as well as the bioproducts produced, such as biosurfactant, bioacid, and biosolvent. The bioproducts produced depend on the inherent capability of the isolate as well as the support of the medium and environmental condition.
From the tests of their capability to grow in hydrocarbons, and live in semianaerobic condition, 12 isolates, were selected and some isolates were found to produce such bioproducts. The selected microbes and nutrient have been experimented by using microbial core flooding apparatus. The result has good prospect for implementation in the oil field.
Intelligent Systems Can Design Optimum Fracturing Jobs
Authors: Mohaghegh Shahab , Popa Andrei , Ameri Sam 
Published: December 2007

ABSTRACT
Many computer software programs have been developed to assist petroleum engineers and scientists in designing hydraulic fractures. These programs use analytical, numerical or empirical methods (or a combination of two or all three methods) to model fracture propagation in the reservoir. The user - which is usually experienced petroleum professional - provides the necessary input parameters to the model. These input parameters include reservoir characteristics, fluid and proppant characteristics and treatment schedule. Usually among the major outputs of these models are the fracture geometry and conductivity.
The goal of this study is to provide a tool that allows the engineer to solve the inverse problem in a fast and efficient manner. Using the tool developed in this study the engineer identifies the desired fracture geometry that she/he would like to achieve and enters this value along with the reservoir characteristics into the intelligent software tool. The software tool would then solve the inverse problem and provides the engineer with fluid, proppant and the treatment schedule that would produce the desired fracture in that particular reservoir.
This new tool has been tested and shows to be capable of designing hydraulic fractures replicating those designed by expert engineers. An innovative hybridization of two virtual intelligence paradigms has been used to develop the methodology that is being introduced in this paper. An industry standard three-dimensional fracturing model (FRACPRO) has been used as the data set generator for the study.