bluuebunny/crossref_metadata_2025_split huggingface dataset:
Exemplary Environmental Impact Assessments as Tools to Optimize Operations and Assure Approvability - Experiences With Projects Around Germany's Largest Oilfield in a National Park and UNESCO World Heritage Site
Authors: Reichenbach Marc , Mattfeld Heiner 
Published: June 2014

Abstract
Exploration and production of oil or gas in protected nature areas require a comprehensive and flexible approach in order to adapt the project to the specificity of the respective conservation objectives. Approvability can only be achieved if all reasonable technical and logistic alternatives, which are able to minimize the environmental impact, are exhausted. These principles are illustrated by experiences from 10 years of handling different projects within Germany’s largest oil field located within a Wadden sea national park: the laying of two pipelines and two sea power cables, the establishment of extensive scour protection and the preparatory planning for four exploration wells.
All projects had to be assessed against the conservation objectives of different regimes: national park, biosphere reserve, nationally protected habitat, European Habitat Directive, European Bird Directive, special species protection and – since 2009 – UNESCO world heritage site. The examples illustrate in which way the technical and logistic concepts were – sometimes radically – changed and adapted to the conservation needs of the area. The main topics to be addressed were:
Strict avoidance of any contamination of the environment (zero discharge principle)
Avoidance of sensitive periods,
Avoidance of raising soil temperature more than two Kelvin,
Minimization of area use
Extensive monitoring
Implementation of compensation measures (revitalization of salt marshes)
These examples of good practice show how an environmental optimization of projects can lead to successful application procedures (even confirmed in court cases). Thus it can enable the exploration and production of oil or gas in protected and environmentally highly sensitive areas. In this way environmental impact assessments should not be seen as static evaluations but rather as a process during which a project is adapted and optimized towards approvability.
A Plant Simulator to Enhance the Process Safety of Industrial Operators
Authors: Manca Davide , Colombo Simone , Nazir Salman 
Published: June 2014

AbstractThe significant impact of human errors on the operation of industrial processes calls for improved methodologies and tools to train both control-room and field operators. Common Operator Training Simulators (OTSs) meet almost exclusively the needs for the formation of Control-Room Operators (CROPs). On the Field Operators (FOPs) side, few contributes have been carried out to improve their training level. The paper presents and discusses a solution for immersive training of industrial operators that allows experiencing the multifaceted scenarios of (real) plant operations. This tool comprises two dynamic simulators that interlink the simulation of the operations underwent in the plant with the replication of abnormal situations, near-misses, and eventually possible accidents. The two-way interaction between a dynamic process simulator and a dynamic accident simulator, when performed in real-time, allows reproducing the experiences lived by industrial operators. These dynamic simulators are the engines that work behind the curtains of an Immersive Virtual Environment (IVE) and make possible the realism (and the associated interest, involvement and enjoyment) of the simulated operations of the plant. The immersive environment is based on Immersive Virtual Reality (IVR), commonly referred to as 3D, where a stereoscopic reproduction of the whole plant, coupled to spatial sounds, increases the situation awareness of the field operators who interact with control-room operators by means of push-to-talk devices.The paper discusses some applications of the Plant Simulator in the Oil & Gas and the polymerization industries that allow reproducing not only specific training case-studies but also real accidents.
Virtual Reality as Effective Tool for Training and Decision-Making: Preliminary Results of Experiments Performed with a Plant Simulator
Authors: Colombo S.. , Nazir S.. , Manca D.. 
Published: June 2014

Abstract
The use of Immersive Virtual Reality (IVR) for training is an idea that is around since long time; the real, unclarified doubt about its use is whether it does really increase performance with respect to traditional methods such as classroom and on-the-job training. The most critical point of traditional training methods is the difficulty to train operators about system’s deviations from nominal conditions. But even the more advanced simulation-supported training approach, commercially represented by the Operator Training Simulator (OTS), is not immune from flaws as it is affected both by the subjectivity of the assessment (making useless the operators’ benchmarking) and by the impossibility of training simultaneously the Field Operator (FOP) with the Control Room Operator (CROP), i.e. team training. The advent of the Plant Simulator (PS) enabled to overcome the inherent limitations of the training methods. But the efficacy of using Immersive Virtual Environments (IVE) was, and to some extent still is, to prove. This paper goes exactly in that direction by explaining the preliminary results of an experiment campaign performed in a PS, which demonstrates the clear benefit of using IVR for training (field) operators. The paper even highlights that, if a PS is used, the benefits are not just limited to the training but can also be extended to operations management.
Perforating High-Temperature Wells
Authors: Bell W.T. , Auberlinder G.A. 
Published: June 2014

Abstract
The recent achievement of new records in well depths has presented a new set of problems to the perforating industry. Resulting extremes in pressures and temperatures have pointed up the limitations of existing tools and explosives, thereby imposing new challenges for equipment and techniques.
This paper describes some of the major problems stemming from deep-well mud pressures and temperatures. Proper techniques for measuring bottom-hole temperatures are discussed. Thermal limitations of currently used wire-line explosive tools and components are emphasized along with recommended ratings and specialized operating techniques. Misconceived notions relating to the capabilities of conventional explosives are treated.
An answer to the trend to deeper wells with higher pressures and temperatures is introduced in the form of a newly developed, high-temperature explosive package for the steel retrievable shaped-charge gun.

Introduction
The extreme bottom-hole temperatures and mud pressures of today's deeper wells present new problems for the perforating industry. As deep tests continue to explore the earth, constant development of equipment and refinement of techniques are required to keep abreast of steadily mounting pressure-temperature conditions.
Deep-well drilling surged upward during the early 1950's. In 1952 less than 10 wells were producing from deeper than 15,000 ft. In 1959 alone, 63 new producers were completed below that depth. Drilling and producing depth records have shown a steady trend upward, resulting in a maximum drilling depth of 25,340 ft, with the deepest successful completion recorded at 20,745 ft.
Should this general trend be maintained, the wireline service industry will, within a few short years, be faced with high pressure and temperature completion problems taxing the capability of existing tools and lab-test facilities.
Optimization of Drainage-Area Configurations To Maximize Recovery From SAGD Operations
Authors: Manchuk Johnathan G. , Deutsch Clayton V. 
Published: June 2014

Summary
Placement of steam-assisted-gravity-drainage (SAGD) surface production pads and subsurface drainage areas in the McMurray formation to maximize the economic potential of an area is a challenging problem. The location of surface pads (SPs) and drainage areas has a large impact on their production performance because of several factors, including variation of bitumen in place, variation of the reservoir base surface, vertical conformance, areal conformance, interaction between different drainage areas and pads, and surface hazards. An optimization algorithm is presented to determine the positions and orientations of SPs and drainage areas over a reservoir area; therefore, the potential for economically recoverable bitumen is maximized. The optimization considers either a deterministic model of the relevant properties or multiple realizations to account for uncertainty. Optimization considers all drainage areas simultaneously to ensure joint optimality of an entire set. The algorithm is demonstrated using two realistic examples that show a significant improvement in potential recovery. The algorithm executes in a reasonable amount of computation time, considering the complexity of the problem.
Quantifying Heat Requirements for SAGD Startup Phase: Steam Injection, Electrical Heating
Authors: Moini Behdad , Edmunds Neil 
Published: June 2014

Summary
A proper and effective startup of the steam-assisted-gravity-drainage (SAGD) well pairs, where both horizontal wells inject steam, is a key parameter to SAGD performance. In the past, a number of investigations have been conducted on the optimum startup strategy and operational procedures; however, fewer studies have modelled the heat requirements of the process. This study proposes an effective practical method that correlates the heat flux inside the horizontal wellbore with the temperature outside the wellbore wall. A transient conductive-heat-transfer equation in a cylindrical coordinate system is adopted for two different startup strategies: (a) variable heat flux (steam circulation in the well pair) to maintain a constant desired temperature at the wellbore wall and (b) constant heat flux (electrical heating of the well pair) to gradually increase temperature and finally reach a desired temperature on the wellbore wall. A novel and simple mathematical technique is presented for each startup approach to evaluate the instantaneous and cumulative heat requirements to keep the wellbore hot. Excellent agreements between the results of the proposed techniques and outputs of a commercial reservoir simulator are demonstrated. Accurate quantitative evaluation of heat requirements for the startup phase of SAGD enables optimum planning for steam requirements and practical design of any other heat sources employed in the process.
Straightline Analysis of Flow Rate vs. Cumulative-Production Data for the Explicit Determination of Gas Reserves
Authors: Ye Peng , Ayala Luis 
Published: June 2014

Summary
Production forecasting and prediction of original fluids in place are important gas-well-performance evaluations which are routinely conducted using rate/time decline-curve analysis. Currently, rate/time decline-curve analysis of natural-gas reservoirs relies heavily on the use of empirical curve fitting of boundary-dominated rate/time production data using type curves or the Arps hyperbolic decline model. In this study, we show that original fluids-in-place prediction and gas-well-performance evaluations can be conducted simply by straightline analysis of boundary-dominated data in flow-rate vs. cumulative-production plots. We first analytically demonstrate that the hyperbolic decline exponent describing the depletion of single-phase volumetric gas reservoirs is not subject to empirical determination from rate/time data. Decline behaviour of gas wells producing at less than full potential is also shown to exhibit a hybrid decline character: hyperbolic during early boundary-dominated flow and exponential at later times. In both cases, explicit calculations of hyperbolic decline coefficients are possible, thus enabling the explicit calculation of gas reserves using flow-rate vs. cumulative-production straightline plots. Numerical and field case studies are presented to demonstrate the applicability and generality of the proposed reserves determination methodology.
Operations Research, A New Discipline of Interest to the Petroleum Engineer
Authors: Allen Fraser H. , Jones Kevin R. 
Published: June 2014

Introduction
A new field of applied science known in this country as "operations research" is making rapid gains as a means of determining the optimum course of action in complex situations. In Great Britain this type of activity is referred to as "operational research". The term "operations analysis" and the abbreviations "OpSearch" and "OR" are in relatively common usage both in this country and abroad. The Germans employ the name "Wirtschaftsforschung" (economic, or management, research) and the Russians, who are now becoming much more active in this type of work, seem to use various terms, one of the more common ones being "operations investigation".
Within this new discipline are a number of techniques especially designed to handle problems involving risk and uncertainty. Probably no industry is so vitally concerned with risk as is the petroleum industry and no professional man is forced continually to deal with such uncertain basic physical data as is the petroleum engineer. The growing interest in operations research in the SPE membership is not surprising.

The Mathematical Model
The first step in formulating the solution to a problem through operations research is to state the problem precisely in mathematical language. It is then necessary to set up what is termed a "mathematical model" of the situation. The development of a mathematical model need not be difficult. In fact almost any engineering calculation, such as a simple pore-volume estimate of reserves, is essentially the same type of thing except that most individuals approach these calculations as a stepwise series of arithmetical calculations. They stop frequently with partial or intermediate answers, weigh the feasibility of the sub-answers, and then proceed. The more sophisticated mathematical-model approach simply demands that the whole series of these steps be set up ahead of time in the form of equations and statements of inequality. The various factors included in these mathematical statements of equality and inequality, as well as the answers themselves, can be restricted within pre-defined limits. This avoids the necessity of pondering the logic of the sub-answers before proceeding.
In-Situ Poisson's Ratio Determination from Interference Transient Well Test
Authors: Shahri Mojtaba P. , Miska Stefan Z. 
Published: June 2014

Abstract
Poisson's ratio is usually determined using well-logging, fracturing data and core samples. However, these methods provide us with a Poisson's ratio which is representative of only near-wellbore regions. In this paper, a technique is proposed by extending currently used pressure-transient testing concepts to include reservoir stresses. More specifically, the interference well test is generalized to find not only conventional flow parameters such as reservoir transmissivity and storage capacity, but also the average dynamic in-situ Poisson's ratio. This is accomplished by using the generalized diffusivity equation, which takes into account flow-induced stress changes.
Firstly, a generalized diffusivity equation is formulated by considering a deformable porous medium. The main goal of the generalized diffusivity equation is to extend current well testing methods to include both fluid flow and rock mechanics issues, and to present a way to determine the rock mechanics-related property, Poisson's ratio, from interference well testing. The line source solution to the diffusivity equation is used to modify the current interference well testing technique. Field data is utilized to show the main steps of the proposed transient well testing analysis technique.
An average in-situ value can be put in practice in different applications requiring accurate value of Poisson's ratio. Some examples of these include in-situ stress field determination, stress distribution and rock mass deformation, next generation of coupled fluid flow-geomechanical simulators, hydraulic fracturing design, wellbore stability analysis and sand production design. Using dynamic Poisson's ratio that could capture the flow-induced stress changes, we would be able to find the stress distribution due to production/injection within the reservoir more precisely. Accurate determination of stress distribution has a significant impact on wellbore stability issues in challenging wells, such as depleted and deep water reservoirs.
A Novel Approach for Efficiently Evaluating Extended Intervals in Coalbed Methane Reservoirs
Authors: Harfoushian Jack H. , Pourabed HamidReza , Moh Hsiao Wun , Torlov Vladislav , Cheong Boon 
Published: June 2014

Abstract
Over the past few years, there has been a surge of interest in using Australia's coalbed methane (CBM) resources to produce liquefied natural gas (LNG) for export, taking advantage of increasing prices and growing global demand for gas. Principally in Queensland, the second largest state, situated in the northeast of the country, there has been significant investment by a number of companies to secure footholds in this resource play. By December 2008, seven proposals for LNG plants had been announced, most involving partnerships between Queensland companies with coal seam gas resources and international petroleum companies.
Most exploration and appraisal CBM wells are tested to determine pressures and coal seam deliverability. As the majority of wells cannot flow to surface naturally, closed chamber tests are conducted, most often in open hole. An alternative testing method employed by a number of operators in Australia over the past 2 years has been the dual packer module of wireline formation testers. Although wireline packers provide a cost-effective and an efficient way of obtaining high-quality pressure transient data sets, they are limited to relatively small test intervals. A new, innovative approach enables testing coal seams of up to 15 m in thickness using wireline formation testers. The new wireline formation testing configuration offers several benefits over conventional drillstem tests (DST) for this application, including rig-time savings. Another benefit of the new technique is the broad range of drawdown and inflow rates, extending coverage from very low- to high-permeability coals. Additional applications used in the field include step-rate tests, the results of which have been applied to assess and rank different coal seams across a number of fields and coal types.
An Innovative Attribute for Enhancing Faults Lineaments and Sedimentary Features During 2G&R Interpretation
Authors: Massala Antoine , Keskes Noomane , Goncalves-Ferreira Liliana , Onu Cajetan , Cordier Philippe 
Published: June 2014

Abstract
Exploration and Development teams are challenged to find and develop fields with increasing complexity. At different stages of seismic interpretation, the introduction and combination of seismic attributes are key to better understand structural and sedimentary features.
The geology derived from seismic attributes must be accurate and of high definition during the exploration, appraisal and production phases of the field. Uncertainties related to fault networks, geobodies mapping and their interfaces may have significant impact on prospect definition as well as on field development plans. In order to reduce these uncertainties, a new attribute Gradient-Coherency Cube (GCC™) has been implemented in Sismage®, a Total In-house software, with a new insight in seismic interpretation.
This attribute highlights both structural and sedimentary features through the seismic volume. The algorithm integrates a 3D (multi-azimuthal) gradient with a maximum correlation search (coherency) which allows detecting subtle lineaments that are not seen, or that are difficult to detect with conventional attribute maps. By enhancing subtle event detection, this new approach helps to:
- improve fault network and geobodies definition
- identify flow barriers encountered by DSTs
- identify relay zones
- reduce uncertainties on fault sealing capacity and communication between panels
- optimize field development plan, well design and geosteering.
Within Sismage®, Gradient coherency cube can be combined with conventional attributes to provide benefits to the overall 2G&R interpretation workflow. By facilitating seismic interpretation, this approach combines the efficiency of seismic attributes with respect to geology and reservoir engineering by delivering optimal well placement and optimizing the field development plan.
Theory and Application of Pressure and Rate Transient Analysis in Unconventional Reservoirs
Authors: Torcuk Mehmet A. , Kurtoglu Basak , Fakcharoenphol Perapon , Kazemi Hossein 
Published: June 2014

Abstract
Pressure and rate transient analyses are reliable methods to estimate effective formation permeability of unconventional reservoirs. The results of such analyses are used to validate or fine-tune the numerical simulation models both for the primary and enhanced oil and gas recovery methods.
Pressure-rate transient test applications in unconventional reservoirs are somewhat different from similar tests in conventional reservoirs because of the extremely tight nature of target formations and the use of horizontal wells as an integral part of well completion and reservoir stimulation. Accordingly, this paper presents theory, mathematical formulation, and application of the numerical and analytical well testing solutions to characterize unconventional reservoirs. The mathematical models pertain to the single-porosity and dual-porosity concepts. In the latter we focused on the issues surrounding the unsteady state (USS) and pseudo steady state (PSS) flow. The models studied in this paper were a 1-D analytical model and a hybrid 3-D numerical model that combines the USS and PSS dual-porosity formulations; a trilinear analytical model and a MINC (Multiple Interacting Continua) numerical model. The 3-D numerical model was compared with the trilinear analytical and MINC numerical models.
In unconventional reservoirs the dual-porosity environment emanates from the auxiliary effect of multi-stage hydraulic fracturing for which the unsteady-state mathematical solutions are more appropriate. The benefits of such solutions are supported by field results, which we will present and discuss. Furthermore, the results of pressure-transient and rate-transient analyses of two oil wells in an unconventional reservoir were presented.
Diagnosing Pressure-Dependent-Permeability in Long-Term Shale Gas Pressure and Production Transient Analysis
Authors: Vera Fabián , Ehlig-Economides Christine 
Published: June 2014

Abstract
The current state of shale gas reservoir dynamics demands understanding long-term production, and existing models that address important parameters like fracture half-length, permeability, and stimulated shale volume (SSV) assume constant permeability. However, observed steeply declining rates may involve pressure-dependent permeability (PDP).
This study accounts for PDP in two potential media: the shale formation and the created hydraulic fractures. Sensitivity studies comparing expected long-term rate and pressure production behavior show that PDP in the shale formation is distinct from PDP in created hydraulic fractures, and both are distinct from behavior without PDP. Successive buildups spaced apart in time reveal PDP behavior, but they do not necessarily indicate whether the permeability changes are in the shale formation or in the hydraulic fractures. The combined buildup and rate-normalized pressure data presentation displays both short-term and long-term transient trends that distinguish the source of the PDP behavior.
Pressure and rate field data demonstrate evidence of PDP in Horn River and Haynesville shale, but not in Fayetteville shale. Successive buildup transients in Horn River shale show evidence of permeability increase while in Haynesville shale they show significant permeability loss. In the Haynesville shale case, the impact of PDP is effectively reduced recovery from the stimulated shale volume defined by productive fracture half-lengths.