bluuebunny/crossref_metadata_2025_split huggingface dataset:
New Mathematical Techniques for the Optimisation of Oil & Gas Production Systems
Authors: Handley-Schachler Sybille , McKie Calum , Quintero Nylian 
Published: December 2007

Abstract
Recent developments in mathematical techniques have allowed the development of a software package to simulate and optimise the flow of hydrocarbons through oil and gas production and distribution networks of arbitrary connectivity and complexity. It has been successfully applied to a wide variety of operational problems including de-bottlenecking, optimisation of compressor strategies and determining the optimal lift-gas allocation to networks of gas lifted wells.
This paper discusses the innovative mathematical concepts at the heart of the algorithm taking account of both optimisation and modelling aspects. It demonstrates how an integrated approach to optimisation and simulation based on Sequential Linear Programming (SLP) techniques provides the user with substantially enhanced flexibility and reliability compared with traditional nodal analysis type approaches and how these benefits can be realised in concrete practical examples.
Descriptions of the behaviour of physical objects in a production or distribution network is commonly given in the form of measured data sets or discrete performance tables rather than analytical functions. A final focus of this paper is the discussion of how such data sets can be used directly and efficiently in an optimisation context.
In-Situ Generation of Carbon Dioxide: New Way To Increase Oil Recovery
Authors: Gumersky Kh. Kh. , Dzhafarov I. S. , Shakhverdiev A. Kh. , Mamedov Yu. G. 
Published: December 2007

Abstract
Miscible/Immiscible carbon dioxide injection is considered to be as one of most effective technology to improve oil recovery from complicated formations, and hard to recover oil reserves, in particular. Application of this technology can increase ultimate oil recovery by 10-15% and even more1. One of the main advantage of this technology is that it can be applied in a wide range of geological conditions for production both light and heavy oils.
Striking illustration of this technology high efficiency is the fact that the number of active carbon dioxide (CO2) projects worldwide sharply increased during last 20 years, from 30-35 in the beginning of 1980s to almost 100 in 2000, while oil production increased from 25,000 BPD to more than 200,000 BPD during this period 2.
One of the main factor restraining wide application of this technology is its dependence on the natural CO2 sources, transportation of CO2, breakthrough of CO2 to production wells, corrosion of well and field equipment, safety and environmental problems etc. Except Hungary reserves of natural CO2 for field application of this technology are not existed in Europe. This restrains wide implementation of CO2 injection not only in many European countries but also worldwide where this technology could be efficiently applied and significantly improve oil production as well as ultimate oil recovery from depleted oil formations. Carbon dioxide enhanced oil recovery may be the key to recovering huge amount of oil from highly watered, depleted, heterogeneous and other type of so called "hard-to-recover" oil reserves. One of the main advantage of proposed technology is eliminating of CO2 negative impact on the environment and strong control of the process.
New understanding of the nature of miscible displacement process when behavior of CO2 can be explain as a "super critical fluid" opens a unique future of oil displacement using this technology.
Results of R & D as well as new approach in estimation of the efficiency of EOR technology application are described below. Proposed technology of in-situ CO2 generation is based on exothermic chemical reaction between gas forming water solution and low concentrated active acids.
Key to a Successful I.O.R. Project - Application of Horizontal Wells
Authors: Palasthy Gy. , Kristof P. , Benedek L. , Pipicz V. 
Published: December 2007

Abstract
A redevelopment strategy for a hydrocarbon producing reservoir in a complex geological environment is presented in this paper. With the application of the IOR technology, the hydrocarbons, which seemed to be hidden in unreachable parts of the reservoir, became economically extractable, increasing the value of the field.
The thin oil column and the large gas cap are trapped in a low permeability turbidite type sandstone reservoir. The thickness of layers separated by interbedded claymarles is less than 10 meters of each. In the first 15-year production period 12% oil recovery could be reached from the reservoir having 10 mD average permeability. At starting of the production the depletion mechanism was gas cap expansion combined with weak water drive (1975-1985). The initially flowing wells started to produce with artificial gas lift in 1980. Water injection was necessary to maintain the reservoir pressure so this technology was launched in 1985. In the early 90's the reservoir had very poor economics because of the low productivity and injectivity of vertical wells. The forecasted production rates had been keeping to the economic limit.
1993 was a mileage in the production history because the first horizontal well was drilled and completed in the reservoir. By the end of 1999 the number of horizontal oil wells was increased up to 20 inducted by the excellent production results.
During this production period, the continuous reservoir monitoring reflected the problems of different phases of exploitation and what kinds of solution alternatives were induced by the integrated interpretation of the increasing information obtained from production history. This paper answers how the production potential of the reservoir could be doubled in the last seven years and how the forecasted ultimate oil recovery increased to over 40%. Redevelopment of this producing object was reached by the IOR technique. Infilling of the producing well pattern and acceleration of exploitation was the key in this mature reservoir. With 3.6 USD/bbl investments an additional 5.2 million equivalent barrel reserve became proved.
3-D Simulation of the Pressure Drop along Horizontal Wells in a Bounded Reservoir
Authors: Ewing Richard , Ibragimov Akif , Lazarov Raycho 
Published: December 2007

Abstract
The mechanism of pressure drop along the horizontal well and its dependence on hydrodynamic and geometrical parameters of the reservoir and the well is in the focus of our work. A model of single-phase coupled fluid flow in porous media and in a horizontal well is proposed. For solving the problem a hybrid analytical/numerical methods is tested. The developed method can be applied to analytical estimation of the influence of the various parameters (geometry of the reservoir (shape factor), length, and radius of the well, and also well/reservoir conductivity) on Production Index.
In our work we consider the whole area of drainage: the wellbore itself, bottomhole zone of the reservoir and the reservoir periphery as three adjoint media with different conductivity. For gluing different type of fluid flows with different geometry special non-overlapping domain decomposition method is developed.
This method allows to reduce complicated fluid flow in 3-D media to a sequence of "simple" flows in homogenous media with standard shape (such as sphere, cylinder or annular cylinder).
Horizontal Borehole Stability in Naturally Fractured Reservoirs
Authors: Zhang Jincai , Roegiers J. -C. 
Published: December 2007

Abstract
For modeling naturally fractured reservoirs, the dual-porosity poroelastic model is effective and accurate to characterize stresses as well as flow fields. A generalized plane strain and dual-porosity finite element solution has been developed for analyzing horizontal borehole stability. Two kinds of failure criteria (spalling and collapse) were included. Results show that horizontal borehole stability depends strongly on the in situ stress state, the borehole orientation, time, mud pressure and fracture characteristics.
The Challenges of Detecting Gas Entries in Horizontal Well by Using Integrated Production Logging Tool, Case Study
Authors: Al-Ali Hussein Ali , Salamy Salam P. , Haq Shahid A. 
Published: December 2007

Abstract
Recently, horizontal wells in Saudi Arabia have been targeted to improve the recovery efficiency and enhance the reservoir drainage of tight reservoirs. Evaluating the performance of high flow rate horizontal wells with high gas-oil ratio and producing below the bubble point is difficult and often non-unique with conventional production logging measurements. The challenges arise from the following reasons:Gravitational segregation of the oil, water and gas in the well bore,Complicated fluid velocity profiles due to phase separation,Mixed fluid flow regimes,Long and undulating well bores.
For the first time in Saudi Aramco, a high flow rate horizontal well with excessive gas oil ratio has been logged with a coiled tubing conveyed integrated production logging tool. The horizontal well penetrated a heterogeneous carbonate formation with a long transition zone. The objectives of running the integrated production logging tool were the following:Determine the flow profile and estimate the entire contributing length,Locate the gas entry points and determine the gas flow rate, if possible,Evaluate the performance of this integrated production logging tool run for the first time in a Saudi Aramco well producing below the bubble point.
This paper presents a case study of such an application in the difficult environment. The results showed that the entire horizontal section was contributing to the total liquid flow. Gas inflow was difficult to quantify with the exception of the toe of the well, where the gas hold-up was higher than 70% and the gas flow rate was successfully computed. The results are discussed in detail and recommendations are made to improve the interpretation of gas inflow in this environment.
Sand Flowback Control in the Rockport Gas Storage Field in Northern West Virginia
Authors: Myers Roger R. , Gottschling John , Kulkarni Shirish , Shaw J. Stanley , Amick Paul 
Published: December 2007

Abstract
Sand flowback can be a big problem in high rate gas wells. Sand can quickly erode chokes, valves and other surface equipment creating potentially dangerous situations for the gas well operating and pipeline companies.
In 1998 and 1999 several different sand flowback or backflow control methods have been applied in Columbia Gas Transmission Company’s Rockport Storage Field. Deformable particles are the latest innovation for controlling sand flowback. Unlike curable resin coated sands and tacky surface-modification agents, deformable particles differ in that they do not "glue" the sand pack in place, but rather mechanically hold it together by dimpling under stress and physically holding adjacent grains of sand firmly in place. A modest weight percentage of deformable particles can easily lock the sand pack in place, resisting the forces brought to bear by gas and fluid flow within the fracture.
The Oriskany Sandstone in the Rockport Storage Field can be classified as a highly permeable formation capable of a withdrawal rate greater than 40 MMSCFD. Stimulation treatments are routinely pumped to improve the Oriskany’s deliverability back to original levels following workover operations. Prior to running deformable particles for sand flowback control, tacky resin-like chemicals and curable resin coated sand were pumped to alleviate the problem.
Modeling Complex Wells in Detailed Geologies
Authors: Fitzpatrick A. J. , Ponting D. K. 
Published: December 2007

Abstract
Modelling complex multi-branch wells requires a detailed treatment of flow within the well and an accurate description of the flow in the near-well region of the reservoir. Modern geostatistical packages provide high levels of detail – ideally this should be maintained in the near-well region whilst keeping the remainder of the reservoir in a less detailed sense to provide boundary conditions.
We describe a model in which a model of the wellbore flow in terms of pressure, velocity and saturation is solved simultaneously with the reservoir flow equations. Constraints at branches, items of well equipment and well target conditions are included in the formulation, as well as the effects of friction, gravity and fluid acceleration. The resulting couplings are carried through into the main linear solution algorithm for the full system. A simpler well model is used as a predictor for the Newtonian solution of the detailed well model.
Intelligent grid coarsening is used in reservoir regions away from the well of interest. Finer detail near the well may be retained from geological modelling. By running a number of geological realizations costing possible outcomes the benefits and risks involved in various well designs may be assessed. An example is given of the evaluation of cost and risk in the choice of well design.
Reservoir Simulation Model for Fractured and Partially Fractured Reservoirs based on PEBI Grids
Authors: von Pattay Patrick W. , Ganzer Leonhard J. 
Published: December 2007

Abstract
This paper presents the implementation of the dual continuum approach (dual porosity/permeability), into a PEBI grid based, general-purpose reservoir simulator.
Experience shows that not all parts of a reservoir will typically require dual porosity/permeability treatment. Sometimes numerical or other restrictions limit the use of a dual porosity/permeability model. The approach presented in this paper takes these aspects into consideration. It allows creating dual porosity/permeability cells wherever the geological attributes (facies, rock type, fracture intensity) imply to do so. The remaining – unfractured – part of the model will be treated like conventional single porosity areas. Therefore, the number of grid blocks and the CPU time required for the flow simulation are minimized.
Fracture and matrix-fracture transfer properties (including shape-factors) are derived from the geological information and fracture intensity. All of this information and data is stored on a cell by cell basis. Furthermore, the presented method does not restrict any of the superior gridding capabilities of the simulator like local grid refinement, fault or well modeling. The equation system resulting from all grid blocks will be solved fully coupled. The flow simulator is based on a multi-purpose, compositional formulation, and copes with systems ranging from single-phase to multi-phase, multi-component fluid flow.
Several examples illustrate the usefulness and flexibility of this modeling approach for accurate and economic simulation of fractured or partially fractured reservoirs.
New Abandonment Technology New Materials and Placement Techniques
Authors: Englehardt John , Wilson Mary Jane , Woody Fred 
Published: December 2007

Abstract
Recent industry concerns related to the increasing number of idle wells in the United States prompted a search by Chevron Environmental Management Company (EMC) for more reliable and cost effective means of well abandonment technology. This paper presents the results of the search, laboratory research and field pilot testing conducted by EMC and the California Department of Conservation Division of Oil Gas and Geothermal Resources. Additionally, the cost analysis and future areas of research are addressed. The successful implementation of the abandonment techniques discussed in this paper show substantial savings on a per well basis while providing a reduction in future liability.
Mapping Air Quality Plumes from Fossil Energy Sources to Assess the Impacts of Secondary Aerosol Development
Authors: Rappolt Thomas J. , Kerrin Stephen L. , Hochheiser William , Ziman Steven , Reheis Catherine 
Published: December 2007

Abstract
In 1998 the U.S. Department of Energy (DOE) embarked upon a feasibility study to research possible ways to sample air quality plumes from fossil energy plumes, especially in their early stages of transport from the source, to better understand the physical dynamics that contribute to plume buoyancy and secondary aerosol deposition. DOE, along with industry partnerships, including the Western States Petroleum Association (WSPA) and Tracer ES&T, Inc., explored concepts of a sampling platform that could easily and safely access plume dynamics to support more accurate modeling and the assessment of fossil energy impacts to ambient air quality. The requirement was to conduct plume monitoring during low and near zero visibility conditions (i.e. fog) which cannot be accomplished using manned flight vehicles or fast moving fixed winged vehicles. The dynamics of the problem require a flexible, slow flying, highly maneuverable sampling platform, from which detailed plume measurements can be made. Hence a remotely piloted airship, under an instrument guidance and control system, offered the best approach. Such a platform, carrying miniaturized sampling/monitoring payloads, provided detailed data concerning the vertical structure of near-term plumes as well as ambient chemistry. This paper presents the various stages of development of Clean Airship 1, a helium filled remotely piloted mini-blimp, planned for use in The California Regional PM10/PM2.5 Air Quality Study (CRPAQS) to conduct detailed mapping of specific fossil energy air quality plume structure.
Beyond Phase I Environmental Site Assessments: Case Studies of Business Environmental Risk Assessments of Oilfield Acquisitions
Authors: Funston R. S. 
Published: December 2007

Abstract
The American Society of Testing Materials (ASTM) has developed a standard practice (E-1527-00) for conducting Phase I Environmental Site Assessments (Phase I Assessment) associated with the transfer of commercial property. The primary objective of the ASTM standard practice is to identify apparent conditions of environmental concern and conduct adequate due diligence so that the buyer can avail themselves of the "innocent purchaser provision" under CERCLA. There are many potential objectives a buyer of oilfield properties might have in conducting acquisition due diligence beyond CERCLA considerations. Because oilfield properties typically have environmental impairments, the threshold considerations for the buyer typically relate to the management and allocation of risk for current and future liabilities between the buyer and seller.
Historically, oilfield sellers have provided either a full or partial indemnification to the buyer for environmental conditions that existed before the date of sale or have provided a due diligence period after the date of sale for the buyer to conduct additional environmental investigations. Today, typical sales are on "as-is" basis where the seller is willing to entertain adjustments in the purchase price for environmental impairments identified by the buyer in a due diligence period before closing.
An Environmental Business Risk Assessment goes beyond the traditional Phase I Assessment to better meet the business needs of purchasers of oilfield properties in "as-is" deals. The scope of the Environmental Business Risk Assessment is tailored to the risk tolerance of the buyer and the nature of the deal. The Environmental Business Risk Assessment provides information the buyer needs to make informed business decisions about allocation of risk as a part of the negotiation of the Purchase and Sales Agreement.
This paper presents four case studies that illustrate how Business Environmental Risk Assessments were conducted to address unique issues associated with the transfer of four "as- is" oilfield property sales in California.
The Development and Use of Risk Acceptance Criteria for the Construction Phases of the Karsto Development Project in Norway
Authors: Berg F. R. 
Published: December 2007

abstract
For the construction phase of onshore plants, standardized acceptance criteria have never been developed within the Statoil Group or the Norwegian landbased industry, although project specific design acceptance criteria was developed prior to the construction of the onshore facilities on the western coast of Norway when developing the huge Troll field some years ago.
This paper focuses on the development process of such criteria for risk acceptance with an emphasis on the construction, commissioning and start-up phases.
The use of risk analyses in plant design, construction and operation is not only a legislatively based requirement in many European countries, i.e. Norway, but also offers a lot of advantageous features to the design process: -Identification of risk and implementation of risk reduction measures in a stage of the project when changes to design and lay out can be implemented relatively easily and with moderate cost compared with implementing the changes after the plant has been built.-Firm and objective decision making on the feasibility of implementing risk reducing measures compared with the rule based approach and above all, decision making based on intuition.-Often a variety of design options can be at hand if verified suitable by risk analyses compared with the rule based approach, which often offers a preset choice of design and construction solutions.
Risk based design and construction allows to a larger degree, tailor made design and construction solutions to be implemented compared with the rule based approach,
In addition, risk analyses can give a substantial contribution to effective implementation of the construction phase and limit the risk both to personnel and material assets.
In order to evaluate risk, risk acceptance criteria is often used and such criteria have been developed for the project, covering: -Risk both to employees and workers being present at site-as well as neighbours in the vicinity of the plant.-Risk to environment.-Risk to material assets.
Two sets of criteria have been established for the evaluation of risk to people, one quantitative set for the strategic assessment of technical risk that can be expressed mathematically and one set to be used when specific work operations or tasks are evaluated.
The later one is being performed by the qualitative use of a risk matrix, where every case can be represented by a frequency of occurrence and a consequence that indicates if the risk is intolerable, tolerable or that can be made tolerable if risk reducing measures are being introduced.
It is firmly believed that the technical risk management system in the this project, including the use of risk acceptance criteria, have been a valuable and decisive success factor in the design and construction of the new facilities.
Establishing Environmental Performance Indicators for the E&P in The Netherlands
Authors: Henriquez Leopoldo R. 
Published: December 2007

Abstract
On June 2, 19951 a voluntary environmental agreement on Implementation of Environmental Policy for the E&P Industry has been signed between the Netherlands’ Government and the Dutch Association of E&P Operators. This so-called E&P
Environmental Covenant, which covers the years 1990 until 2010, comprises quantified environmental targets which should be achieved within a certain period in time. Each individual E&P operator has to provide the Government for a Company Environmental Plan every four years describing the planned reduction measures to achieve those targets. Also yearly the E&P operator has to present a progressreport to the Government. The Government also expects the E&P operator to implement the planned reduction measures through an Environmental Management System based on the ISO 14000 standards. The effectiveness of the implementation is assessed on the basis of environmental performance indicators and by applying benchmarking and a ‘Best In Class’ mechanism.