bluuebunny/crossref_metadata_2025_split huggingface dataset:
Temperature Field Measurements and Computer Program Predictions Under Cementing Operation Conditions
Authors: Merlo Antonino , Maglione Roberto , Guillot Frederic , Bodin Dominique 
Published: December 2007

ABSTRACTDuring cementing operation it is important to have a good control of the setting time. The setting time is strongly affected by the wellbore temperature. So circulating temperature is one of the most important parameters for the design of cementing operations.In order to better control this parameter, measurements were performed on a deep well in cased hole.Temperature were measured at different depths on a deep vertical well with a 7" tie back casing in hole before and during mud circulation, in order to accurately estimate the temperature profile in the well. Very few data have been published in the literature with casing in hole.The circulating measured temperatures are compared with calculated temperatures by means two computer programs, developed by two different Companies.It is shown the good agreement for each depth between the field measurements and the calculated results. This field case can be used as a base for the validation of the other temperature computer programs.A description of the analytical model of the computer programs is presented in the paper.The computer program calculates the temperature profile of the fluid in the casing, in the annulus and in the formation for each measured depth of well during circulation.The heat exchange between the casing, the annulus and the formation is described by means of integration of the equations of conservation of energy, applied to a control volume inside the casing, the annulus and the formation.Some justified assumptions are made to obtain the desired partial differential equations...,Some correct boundary and initial conditions are defined for the solution of the differential equations of energy.
Relative Permeability Measurements: An Inter-Laboratory Comparison
Authors: McPhee C. A. , Arthur K. G. 
Published: December 2007

ABSTRACTEvaluation of the comparative performance of four service contractors has highlighted often inexplicable inconsistencies and discrepancies in laboratory waterflood data, despite using similar test cores, identical test fluids, and similar test procedures. Depending upon the methods laboratories prefer to establish initial water saturation, and their favoured waterflood rates, the difference between oil initially in place and residual oil saturation varied from 10 to over 60 saturation units. Duplicate tests carried out by the co-ordinating laboratory failed to replicate two laboratories’ results, and showed that both residual oil saturation and relative permeability are rate-dependent, but relative permeability appeared to be viscosity-independent. Although low rate "bump" floods might yield appropriate end-point data for water-wet rocks, virtually all laboratory waterfloods invalidate classical interpretation theory. Analytical models must therefore allow for capillary pressure, wettability, heterogeneity and viscous instability. Recommendations on the key steps in representative laboratory core flood test design include appropriate wettability conditioning, initial water saturation, selection of viscosity ratio and flow rates, and quality control procedures.
Simultaneous Determination of Capillary Pressure and Relative Permeability of a Displaced Phase
Authors: Kokkedee J. A. 
Published: December 2007

ABSTRACT
A procedure is presented for the simultaneous determination of capillary pressure and tail-end relative permeability from a continuous injection experiment at different flow rates. This is achieved through matching the experiment with numerical simulations. In our experimental setup, a core plug is placed between a water-wet and an oil-wet filter while fluid is injected continuously into the core. The resulting pressure drop over the core contains information on both the capillary pressure and the relative permeability of the displaced phase. With an optimisation procedure, built around a numerical simulator, these key reservoir parameters can be extracted from the measured differential pressure. The validity of the procedure is discussed and whether the capillary pressure and relative permeability curves obtained are unique is examined. Application of the procedure to sandstone, provides results which are in good agreement with those obtained with other techniques. The automatic matching procedure developed can, in principle, be applied to every experiment that can be simulated with a standard simulator. As an example, the calculation of the capillary pressure and tail-end relative permeability from equilibrium centrifuge data is discussed.
Accurate Insitu Compositions in Petroleum Reservoirs
Authors: Fevang Øivind , Whitson Curtis H. 
Published: December 2007

Abstract
This paper describes experimental procedures for determining accurate estimates of original insitu reservoir oil and gas compositions. The proposed equilibrium contact mixing (ECM) method can use samples which are clearly not representative of insitu fluids (e.g. due to nearwellbore multiphase behavior, reservoir depletion, or separator sampling problems). ECM procedures are recommended for saturated, undersaturated, and depleted reservoirs.
Examples are given for reservoir fluids ranging from very lean- gas/black-oil systems to highly volatile gas/oil systems. Furthermore, it is shown that the proposed ECM method can be used to obtain depth-weighted average insitu compositions in reservoirs with gravity- induced vertical compositional gradients.1
The Peng-Robinson (PR) and Soave-Redlich-Kwong (SRK) equations of state (EOS) are used in calculations, with extensive characterization of the C7+ fractions. Static PVT experiments and radial 1D/2D compositional simulations of typical fluid-sampling conditions are used to verify the proposed methods.
Partly due to the success of the ECM method, the traditional definition of a "representative" sample is reconsidered, and a more general definition is recommended. The general definition ("reservoir-representative") is any sample produced from a reservoir, where the measured composition and PVT properties are of good quality. The traditional definition ("insitu representative") is a special case where the sample represents an insitu reservoir composition at a specific depth (or an average composition for a depth interval).
Separator sampling of gas condensate and volatile oil reservoirs is widely used. We present an analysis of traditional separator sampling methods, potential errors in separator sampling, and a critical evaluation of the "isokinetic" sampling method. Isokinetic sampling is currently used to sample separator gas streams when separator liquid "carryover" is suspected. Problems with the isokinetic method are discussed, and we suggest field and laboratory measurements which are needed to confirm the validity of isokinetic sampling.
Development of a Thin Oil Rim With Horizontal Wells in a Low Relief Chalk Gas Field, Tyra Field, Danish North Sea
Authors: Nykjaer Olav 
Published: December 2007

Abstract
This paper presents the history of the development of an oil rim in a chalk gas field. In a low relief gas field, oil rim development is problematic because the proximity to fluid contacts leads to gas and water coning and a significantly decreased oil production. This problem has been reduced in Tyra by developing the oil rim with horizontal wells. The best oil wells are in areas where gas production is impaired by tight chalk immediately above the gas-oil contact, and where the oil rim Is thickest.
The field was initially developed as a gas field due to poor production tests of the oil rim during the appraisal of the field. An understanding of the distribution of oil led to the drilling of a successful oil rim well. The advent of horizontal drilling increased the scope for oil rim development and accelerated the drilling of oil rim wells. Extensive reservoir simulation work provided the reservoir management tool for the planning of an oil rim development under the constraint of a gas sales agreement. H has resulted in a plan for further development of the Tyra gas field. According to the plan additional gas Injection will in a period of seven years result in low net annual gas off-take from the Tyra gas production wells and the main production will instead come from horizontal wells in the oil-rim. During this time the majority of the oil reselrves will be produced.
Risk Assessment and Management in IOR Projects
Authors: Goodyear S. G. , Gregory A. T. 
Published: December 2007

ABSTRACT
The application of IOR techniques is one of the investment opportunities open to Exploration and Production companies. A project will only go forward if the perceived balance between the rewards and the risks is acceptable. IOR projects may be ruled out because they are considered to involve significantly higher risks than conventional developments. Therefore, some means of evaluating the actual level of risk may be required if the full economic benefits from IOR techniques are to be realised.
Risk assessment is a key element in safety cases, where a well-established methodology for quantifying risk exists. This paper discusses the extension of these methods to IOR project risk assessment. Combining reservoir and IOR technique uncertainties with their impact on project performance allows project risk to be better quantified. The results of the risk assessment are presented in terms of a "risk-reward" diagram that plots the probability surface for possible project outcomes as a function of NPV (reward) and exposure (risk).
The outcome of a risk assessment can be used proactively to mauage risk by identifying actions to reduce the probability of project outcomes with low NPV and high exposure. Risk management strategies are identified, including improved project design, key data acquisition and contingency planning. It is argued that IOR projects should be optimised by considering economic and risk factors together.
A generic polymer project is used to illustrate the application of risk assessment and risk management techniques. A superficially attractive unrisked project is shown to be unacceptable when a risk assessment is performed However, by applying risk management and changing the project design appropriately, it is possible to achieve significant risk reduction with little loss in economic performance, compared to the unrisked base case project.
Reconciliation of Field Observations in a North Slope Reservoir Through Pore Fluid Microvisualisations
Authors: Gamble I. J. A. , Butler D. C. , Sinock K. J. 
Published: December 2007

ABSTRACT
Log data from a North Slope field indicated particularly high initial water saturations in the major reservoir zone, often in excess of 50%. Despite this, well tests yielded dry oil from the producing intervals, implying that the mobility of the connate water was negligible. A pore fluid microvisualisation technique was used to examine the initial distributions of fluids within core samples, in order to reconcile the apparent inconsistencies in the field observations.
The amount and distribution of initial water was controlled by the proportion of micro-porosity. Connate water resided primarily within chert, although some was associated with pore-filling kaolinite. This clay mineral was partly water filled and partly oil filled, depending upon the capillary pressure applied to the core sample to acquire Swi. Very little water was held in a conventional manner as thin films on quartz surfaces. Core flow tests confirmed that mobility of water was essentially zero, even at the highest water saturations.
The technique was also used to examine the distributions of fluids at waterflood residual oil saturation. The rock was predominantly water wet in character and classical 'snap-off of residual oil was observed, with the oil being trapped as isolated 'blobs' or as multi-pore 'ganglia'. Saturation and distribution of oil after waterflooding was found to depend upon the flow rate and flow regime used.
Microvisualisations provide a unique insight into fluid distributions at Swj and Sorw. For this reservoir renewed confidence in saturations derived from well logs was realised.
Assessing the Relative Permeability of Heterogeneous Reservoir Rock
Authors: Jakobsen S. R. , Ingsøy Pål , Braun Ted , Guo Ying , Aga Magnar 
Published: December 2007

ABSTRACT
Reservoir engineers are often faced with heterogeneous core material, for which conventional methods of estimating relative permeability are susceptible to error and may lead to incorrect conclusions regarding displacement efficiency, wettability and reservoir performance. This paper focuses on new techniques for judging the validity of relative permeability data obtained on heterogeneous cores.
Numerical simulation is used to quantitatively analyse the impact of typical heterogeneities. For unsteady-state tests analysed by conventional methods, it is shown that typical heterogeneities influence relative permeability in a systematic way, and that parts of the measured curves still may provide valid data. The error introduced by heterogeneities is quantified and correlated with the Dykstra Parson coefficient. Further, it is shown that the steady-state technique is more robust than the unsteady-state measurements in case of stratified material.
SCR-Based Feed Control Enables 100% Core Recovery in Slim-Hole Wildcats
Authors: Spoerker H. F. , Dhindsa J. S. 
Published: December 2007

Abstract
As part of a multi-year slim hole drilling project in Venezuela, large scale automization of the drilling/coring process has been achieved. An SCR-based constant feed control system has been implemented and proven to be a distinct advantage over standard weight-on-bit (WOB) oriented controls. The rather abrupt feeding when trying to hold WOB constant resulted in feed-off cycle frequencies of approximately 1 s -1 propagating through the drill string and thus inducing core breakage and jamming in the core barrel.
To avoid these axial peak loads, the system has been modified to feed off at a constant, driller-defined rate, slowing down gradually from this rate when approaching pre-set WOB maximum limits. This results in the drill string smoothly "following" the core head drilling off, allowing the core to continuously travel up the inner core barrel. Even laminated formations with ROP variations between &lt;10 and &gt;40 ft/hr were successfully drilled without core jamming and sustained 100% core recovery. Using this system, the driller can match bit and formation characteristics for a given rotational speed to achieve optimum ROP at reduced bit wear.
The system is completely based on the control of the drill string movement using the drawworks' DC motors and SCR system drive, thus eliminating the need for additional sensors in the derrick. It can be retrofitted to any SCR driven rig at low cost in minimum time. It's application is specially suited for slim hole drilling where the constant, smooth feed limits WOB fluctuations to only +/− 200 lbs, but can be used during any drilling operation, improving drilling performance and extending the service life of downhole equipment. This paper describes the technical realization of the system, its application during 4 1/2 inch coring operations and recommendations how to use it for optimum drilling performance and core recovery
Use of Uncertainty Techniques to Determine Input Parameters for a Gas Sweetening Plant
Authors: Comer A.G. , Campbell John M. , Menzie Donald E. 
Published: December 2007

This paper was prepared for the Gas Industry Symposium of the Society of Petroleum Engineers of AIME, to be held in Omaha, Nebr., May 21–22, 1970. Permission to copy is restricted to an abstract of not more than 300 words. Illustrations may not be copied. The abstract should contain conspicuous acknowledgment of where and by whom the paper is presented. Publication elsewhere after publication in the JOURNAL OF presented. Publication elsewhere after publication in the JOURNAL OF PETROLEUM TECHNOLOGY or the SOCIETY OF PETROLEUM ENGINEERS JOURNAL is PETROLEUM TECHNOLOGY or the SOCIETY OF PETROLEUM ENGINEERS JOURNAL is usually granted upon request to the Editor of the appropriate journal provided agreement to give proper credit is made. provided agreement to give proper credit is made. Discussion of this paper is invited. Three copies of any discussion should be sent to the Society of Petroleum Engineers Office. Such discussion may be presented at the above meeting and, with the paper, may be considered for publication in one of the two SPE magazines.

Abstract
A primary consideration of an engineer in the selection or design of a gas processing unit is its capacity and its processing unit is its capacity and its sales volume. If only one source of gas of a uniform composition is available, the input parameters to the unit are fixed within very narrow limits. However, if two or more sources are commingling the gas supplied to the unit, then the designer is forced with the difficult decision of ascertaining the correct input parameters to use as design criteria. The authors of this paper found that the use of the principles of uncertainty would give the best engineering estimate to this latter case.
To illustrate the use of uncertainty techniques for this application, the authors' wrote a Fortran IV Computer program utilizing the Monte Carlo method. Several hypothetical problems are presented and solved. problems are presented and solved. In each example, the classical approach or using a straight volumetric calculation gave values for the acid gas composition which, if used without modification, would have resulted in an underdesigned unit. In each of the examples investigated the acid gas composition for each supply source was allowed to follow a normal distribution in order to compare the differences involved in this particular assumption.
Numerical Coning Applications
Authors: Coats K.H. , Henderson J.H. , Modine A.D. 
Published: December 2007

Discussion of this paper is invited. Three copies of any discussion should be sent to the Society of Petroleum Engineers office. Such discussions may be presented at the above meeting and, with the paper, may be considered for publication in one of the two SPE magazines.

Abstract
This paper discusses the effect of completion interval on aquifer storage operations. The study was performed using a single-well, two-dimensional reservoir simulator model.
Results are presented for two reservoir geometries, a homogeneous and a highly stratified heterogeneous reservoir model. For both geometries, the effect of completion interval upon such parameters as water arrival time, injectivity and productivity indices, and gas bubble thickness were studied for two different rate schedules. Results showed that completion interval did not affect bubble thickness for the homogeneous model, but did show some effect for the heterogeneous model. For both models the depth and length of completion interval did affect such parameters as water arrival time, water parameters as water arrival time, water cut and productivity indices.

Introduction
Well completion intervals and depths used in aquifer storage operations frequently consist of five or ten feet perforated intervals located immediately below the caprock. In some cases the gas bubble thickness as estimated from neutron logs seems to stabilize or at least grow very little from year to year when thickening would be expected due to gravity drainage and/or inventory growth during the early life of the storage operation.
The Use of Integrated Software for Improved Reservoir Management
Authors: Dria M. A. , Avonstam Peter 
Published: December 2007

Abstract
Recent geoscience and engineering software developments, and 3-dimensional visualization in particular, ease construction and utilization of detailed geological descriptions in reservoir simulation. This enhances the interaction between asset team members such as geophysicists, geologists, petrophysicist, reservoir engineers, and production engineers, and provides the media to share concepts, data, and ownership in the creation of a consistent geo-engineering model. This paper provides insight into what is software integration, what are the current industry trends, and how software integration impacts the way reservoir studies are conducted. Advantages of integrated software in reservoir management are both technical and timesaving in nature. These advantages are discussed. Examples of integrated studies provide background material for the discussion of these questions. The authors also discusses the many remaining challenges the geoscience/engineering software industry faces and how it must respond in meeting these challenges.
Physico-Chemical Characteristics of Polyacrylamide Solutions after Mechanical Degradation through a Porous Medium
Authors: Noïk Ch. , Delaplace Ph. , Muller G. 
Published: December 2007

ABSTRACT
Mechanical degradation of polymer solutions is an important problem which has to be assessed before injection into a reservoir. The main consequence is a viscosity loss due to macromolecules breakage which can strongly reduce the polymer solution effectiveness in controlling the water mobility inside the reservoir. Flow experiments have been performed by recirculating hydrolyzed polyacrylamide solutions through a small pack of sand particles. Polymer characteristics determined by viscometric and light scattering measurements have been analysed before and after injection at various flow rates. A normalized rate of degradation was defined by comparing the initial and final values of the intrinsic viscosity of solutions. The parameters investigated were: polymer concentration, molecular weight, concentration and nature of electrolytes.
Alcohol-Free Chemical Flooding: From Surfactant Screening to Coreflood Design
Authors: Sanz C. A. , Pope G. A. 
Published: December 2007

ABSTRACT
Alcohol-free micellar solutions which yield high solubilization ratios (15-30 cc/cc), high final oil recoveries and eliminate the use of alcohol, a costly chemical, have been formulated for application in chemical floods.
A major difficulty was to preclude gels, liquid crystals, macroemulsions and precipitates along the composition path during a chemical flood. A screening strategy was applied to select among combinations of quite different surfactant structures. Corefloods were run with a blend of pure surfactants (C180CH2· CH2-S03Na, 8øC16SO3Na and 7øC14SO3Na), an ethoxylated sulfonate (6C16(OCH2·CH2)2 SC3 Na and a blend of an internal olefine sulfonate and a petroleum sulfonate. A slug size-efficiency curve obtained from corefloods with screened alcohol-free formulations, was compared to previous data with a conventional petroleum sulfonate/alcohol system (TRS 10-410/IBA) at 65° C taken as our basecase.
An equimolar blend of an internal olefin (C20-C24) sulfonate and a petroleum sulfonate gave a final oil recovery of 94% with a 13% Pvi slug size, 3v% surfactant concentration, at 80° C. When the slug size was reduced to 3% Pvi, the oil recovery still was 80%. Final results are compared to the basecase and other combinations tested and reported under comparable conditions.
High Temperature Synthetic Cement Retarder
Authors: Eoff L. S. , Buster Doug 
Published: December 2007

Abstract
A synthetic cement retarder which provides excellent retardation and compressive strength development has been synthesized. The response properties and temperature ranges of the synthetic retarder far exceed those of commonly used retarders such as lignosulfonates. The chemical nature of the new retarder is discussed and compared to another synthetic retarder.