bluuebunny/crossref_metadata_2025_split huggingface dataset:
Improved Well Productivity Utilizing a Foamed Borate Crosslinked Fluid
Authors: Pierce A.D. , McNally A.C. , Armstrong R.L. 
Published: December 2007

Abstract
In the past few years, the Boonsville Bend Conglomerate gas field has been fractured utilizing a foamed (70 - 75% nitrogen) organometallic crosslinked fluid. Recent studies illustrate that organometallic crosslinked foamed fluids damage the proppant pack permeability greater than 60% with breaker at 140F. Damage of this extent greatly reduces the outcome of the stimulation treatment. A guar based fluid utilizing a new, organically complexed borate crosslinking system and nitrogen mixed at 60 - 65% was selected. This fluid shows superior rheology properties and excellent clean break characteristics. An independent consortium has confirmed greater than 85% retained permeability with breaker at 140F. Stability of the system is such that increases in sand concentrations from three pounds per gallon up to five pounds per gallon have been incorporated into the designs. This redesign has lowered overall fluid volumes, even thought the quality of the foam is ten to fifteen percent less.

Introduction
Recently, wells fractured with an organometallic crosslinked foam showed low fluid recovery, poor production performance, and post frac sand production in the bend conglomerate formation in the Wise and Jack county areas of North Central Texas. The test wells used in this discussion were all in the Atoka group of the Boonsville field area of North-Central Texas. This group consists of five systems: the Boonsville fluvial-deltaic, the Smithwick pro-delta/basin-fill, the Grant deltaic, the "Pregnant" pro-delta/basin-fill, and the Brazos fluvial-deltaic. The "Conglomerates" of the Boonsville system are the primary reservoir for the field. They consist of fine to coarse grained sandstone and grade more commonly to fine to medium-grained poorly sorted, subrounded conglomerates and occasional thin, widespread limestone. The main constituents of the "conglomerates" are quartz with chert and feldspar, and commonly gluconite, especially in the lower part of the Atoka.

FRACTURE FLUID HISTORY
The use of a nitrogen foamed CMHPG polymer based fluid, utilizing titanium and zirconium as the delayed crosslinker was initiated due to several benefits of the fluid. The main advantages were good thermal stability and reduced tubular friction pressures. However, current research indicates that up to 80% of the proppant pack permeability can be damaged using a transitional metal crosslinker.
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Encapsulated Breakers in the Red Fork Formation of the Anadarko Basin: A Case History
Authors: Waters G. A. , DeLeon D. D. 
Published: December 2007

ABSTRACT
Since their introduction, encapsulated breakers (EB) for water-based fracturing fluids have gained wide acceptance within the petroleum industry. Their use has improved the retained fracture permeabilities over those previously attained. The net results have been improved production and a greater return on investment for the operator.
While various laboratory experiments have confirmed the need for maximum breaker concentration1-4 a field test was desired to document the effect of the high breaker concentrations attainable with EB. Therefore, a case study of 23 wells, 13 of which contained EB, was undertaken in the Red Fork formation of the West Butler and Strong City fields in the Oklahoma counties of Custer and Roger Mills (Fig. 1). Post-fracture production performances were evaluated to confirm the effectiveness of the EB. These field tests show that increased breaker concentrations do indeed improve well performance.
Reproducibility of Flow Computer-Generated Gas Volumes Using Averaged Flow Parameters
Authors: Haefele R. M. 
Published: December 2007

ABSTRACT
Remote electronic flow computers installed on orifice meters calculate, as part of their audit data trail, averages of the variable flow parameters (Pf - flowing pressure, hw - differential pressure, Tf - flowing temperature) for each time interval defined by the flow computer. Because of the interdependency of the flow parameters within the AGA-3 gas flow equation, the volume produced by applying that equation to the averaged parameters can often be significantly different from the sum of the instantaneous volumes calculated by the flow computer using the same equation. Because of this calculation-induced volume shift, averaged flow parameters should not be used to recalculate the volumes produced by flow computers unless the averages have first been adjusted to reproduce the summated volume for the time interval in question.
A New Model for Production Decline
Authors: Rodriguez Fernando , Cinco-Ley Heber 
Published: December 2007

ABSTRACT
An analytical solution is developed in this paper to forecast the production behavior of two-dimensional closed-boundary reservoirs producing from multiple wells under constant different bottomhole pressures. Wells are represented as line sources arbitrarily located in the domain of the reservoir; damage is considered. Solution is obtained through combination of Laplace transformation and Green's functions Methods.
The production decline of the wells during the boundary dominated flow period is shown to be of a modified-exponential nature: qwDj(tD)=qwDj∞+(qwDj0−qwDj∞)exp(−DtD),j=1,2,  ..nw. When all wells produce at the same bottom-hole pressure, it is shown that qwDj∞=0 and production declines exponentially. It is also shown that the production decline of the reservoir is in all cases exponential: qD(tD)=qD0exp(−DtD), being qD0=∑j=1nwqwDj0.
It is found that the decline coefficient, D, is the same for the reservoir and for each of the wells. D depends on the size and shape of the reservoir as well as on the number of wells, its location and damage. Parameters qwDj0,qwDj∞ and qD0 besides of depending on the same parameters as D, also depend on the bottomhole pressures of the wells. As expected, production under unequal bottomhole pressures or under irregular wells-reservoir patterns, yield uneven well productions. It is also found that stimulation, or damage, of a single well modifies the entire production characteristics of the wells-reservoir system. A simple method of analysis that provides the production decline parameters qwj0,  qwj∞, j=1,2,  …,nw and D, is developed.
Insights Into Good Hot Oiling Practices
Authors: Mansure A. J. , Barker K. M. 
Published: December 2007

ABSTRACT
One of the common oil-field wellbore problems is paraffin deposition. Even though hot oiling is usually the first method tried for removing paraffin, few operators appreciate the limitations of hot oiling and the potential for hot oiling to aggravate well problems and cause formation damage. Several hot oiling jobs were monitored to understand "old pumper's tales" and the dynamics of hot oiling. The field work was supported with laboratory analyses of the oil and calculations of thermal effectiveness. This limited study has shown that the chemical and thermal processes that occur during hot oiling are very complex and that there are significant variations in practices among operators. Key findings of this work include: (1) During a typical hot oiling job, a significant amount of the oil injected into the annulus goes into the formation, and hence, has the potential to damage the formation. (2) Organic particulates in stock tank oil may not completely dissolve/melt as the oil passes through the hot-oiling-truck heat exchanger, hence, these particulates may plug the formation. (3) Hot oiling can vaporize oil in the tubing faster than the pump lifts oil. This interrupts paraffin removal from the well, and thus, since the wax is not removed from the well, the wax is refined into harder deposits, can go deeper into the well, and can stick rods. These insights have been used to determine good hot oiling practices designed to maximize wax removal and minimize formation damage.
Part of this work was performed by Sandia National Laboratories operated for the United States Department of Energy under contract DE-AC04-76DP00789.
Basic Approach to the Application of Field Gas Compressors for Production Engineers
Authors: Shafer J. L. 
Published: December 2007

ABSTRACT
A basic approach to the application of gas compressors is presented to explain the effect of clearance in a reciprocating compressor cylinder. Compression efficiency is not affected by clearance volume, because most of the work required to compress the gas in the clearance volume is recovered when it expands back to suction conditions. Use of clearance enables the operator to maximize the horsepower in a unit by using larger cylinders. Purchase or lease of a well designed unit awards the operator with a broad range of operating conditions. This becomes cost effective. Otherwise, changing out units becomes expensive and time consuming to the producer.
Enzymatic Breaker System for Nondamaging Removal of Cellulose-Based Blocking Gels
Authors: Rickards A. R. , Tjon-Joe-Pin R. M. , Boles J. L. 
Published: December 2007

ABSTRACT
An external breaker system, consisting of a combination of enzymes, has been used to remove polymer damage at low to moderate temperatures. This enzyme mixture produces a stepwise breakdown of cellulose polymers at temperatures ranging from 60 °F to 140°F. The polymer is initially reduced to D-glucose and cellobiose. The complete hydrolysis of the cellobiose is subsequently afforded by the enzyme combination. The entire hydrolysis of the polymer occurs rapidly; therefore, the enzyme complex can be applied as an external breaker after the workover operations have been completed. Post workover injection of the enzyme complex allows blocking gels to retain maximum strength during operations. The enzyme combination is compatible with the brines used to prevent damage from swelling clays. The result is a blocking gel that is reduced to a clean non-viscous fluid that is easily recoverable.
Interpretation of Early- and Late-Time Filtration Phenomena of Crosslinked Polymer Cakes in Front of Long Cores
Authors: Mayerhofer M. J. , Staubmann H. U. , Economides M. J. 
Published: December 2007

Abstract
A potentially important component of the total pressure drop from a fracture into a formation during hydraulic fracture stimulation is that across a polymer invaded zone. Following experimental work with long cores (up to 60 cm-long) and with permeabilities up to 5 md it was determined that the polymer invasion for a zirconate-crosslinked HPG-system has not particular significance and is thus neglegible compared to the very dominant filtercake. The observed early-and late-time filtration phenomena were decribed using a numerical cake layer model and verified by experimental measurements. It is shown that the early-tiine ’’hyperbola" is not a result of polymer invasion but is caused by a changing pressure differential across the filtercake at the beginning of the filtration experiment.
Laying Sand Plugs with Coiled Tubing
Authors: Chambers M. J. 
Published: December 2007

ABSTRACT
A successful technique for placing accurate amounts of sand inside casing was developed for the Western Operating Area (WOA) of the Prudhoe Bay Unit (PBU) on the North Slope of Alaska. Using coiled tubing and a multistage pumping schedule, a sand plug can be laid in one, time-saving operation.
The experience gathered from more than 100 field operations performed in the WOA during 1991 and 1992, in varying downhole conditions, provided for the refinement of the operational steps; allowing the first and each succeeding stage to be adjusted, in situ, for the manner in which the sand plug ‘behaved’ as it was placed.
Inflow Performance of a Horizontal Well Intersecting Natural Fractures
Authors: Guo Genliang , Evans R. D. 
Published: December 2007

ABSTRACT
Analytical single phase and multiphase pseudo-steady state inflow performance equations for a horizontal well intersecting natural fractures are derived. The single phase inflow performance solutions are obtained by combining pseudo-steady state solutions of a horizontal well in a homogenous reservoir block and of a vertical fracture in a sub block. The effects of permeability anisotropy, wellbore eccentricity and fracture characteristics are considered. Multiphase inflow performance equations are derived by incorporating relative permeability and capillary pressure characteristics into the corresponding single phase solutions.
Results are presented using the equations to estimate the optimum number of horizontal wells which should be drilled to drain a given naturally fractured reservoir.
Horizontal Wellbore Collapse in an Anisotropic Formation
Authors: Ong See Hong , Roegiers J-C. 
Published: December 2007

ABSTRACT
This paper discusses an anisotropic model for assessing the mechanical stability of a deep borehole subjected to an internal wellbore pressure and a far-field stress tensor. The model consists of the three-dimensional analysis of stress concentrations around an inclined borehole due to the far-field stress tensor, combined with internal wellbore pressurization, flow and thermally induced stresses to give an approximate non-coupled solution. The model utilizes a generalized three-dimensional anisotropic strength criterion for assessing borehole collapse which is one manifestation of shear failure. Parametric studies indicated that the stability of the wellbore is significantly influenced by high degrees of rock anisotropy, high in-situ stress differentials and excessive wellbore cooling. Pore pressure and porous elastic constant also affect the stability but these effects are less pronounced.
A Second Youth for a Mature Oil Field: Flank Development and Appraisal with Horizontal Wells, Rima Field, South Oman
Authors: van Kossem S. J. , Brouwer G. C. , Lensvelt M. M. A. M. 
Published: December 2007

ABSTRACT
Development of the relatively short undrained oil columns in the flanks of the Rima Field, Oman is an attractive strategy with a view to minimizing water production, increasing productivity and improving sweep efficiency. This paper presents the results of the planning, drilling and initial production phases of four sub-horizontal wells that have been drilled in the flanks of the field to date. Based on the geological and reservoir engineering studies it was clear that flank development with dip-oriented wells is a better strategy than development with strike-oriented wells. The most compelling reason is the flexibility which is retained for future horizontal infill campaigns. The field would not be fenced off as it would be by a ring of strike oriented horizontal wells, and the uncertainties in volumetries are reduced. The initial results show very high oil production rates in the horizontal wells proving the concept of flank development with dip-oriented sub-horizontal wells. Tail- end appraisal proves to be a very important secondary objective for these wells, given the poor quality of seismic data in the Rima Field.
Low-Impairment Mud System for Drilling Horizontal Wells Through Clastic Reservoirs in a South Oman Oil Field
Authors: Glendinning D. R. , Zwolle Simon , Vancura John 
Published: December 2007

Abstract
This paper discusses the development, field experience, cost aspects and the consequences of using a low-impairment drilling fluid system for drilling horizontal wells targeted on clastic reservoirs in a South Oman oil field in the concession area of Petroleum Development Oman [PDO], The first horizontal well was drilled in January 1990 and by October 1992 a total of twenty three wells had been drilled and completed in the field. The first five wells were drilled using conventional water based systems. But once the horizontal well scenario had been proven, subsequent wells were drilled with a fit-for-purpose low-impairment drilling fluid system formulated for specific hole sections. Progressive changes in well and mud design, as well as the optimization of drilling practices, have resulted in significant reductions in drilling times and well costs and increased well productiviities.
Safety Management System
Authors: Carrier H. A. 
Published: December 2007

ABSTRACT
This paper presents a brief history of the development and implementation of ADCO's Safety Management System, provides an overview of each of the system's component parts, and outlines ADCO's plans for the way ahead.
Management concern for the welfare of its employees, coupled with increasing shareholder and public awareness, prompted ADCO in 1991 to review the way in which it managed safety and as a result, to make some significant changes.
Traditionally, ADCO (in line with many other large industrial organisations) measured corporate safety performance using two indicators : accident frequency and accident severity. The review indicated that ADCO's somewhat limited outlook needed to be broadened. In turn, this lead ADCO to reconsider its safety objectives with a new focus on the need for major improvements in safety performance that would be both sustainable and ongoing. The result of this corporate review was ADCO's Safety Management System (SMS) : a system designed to cover a broad band of safety activities and provide positive management control.
The SMS is made up of several component parts, from the various committees and plans to standards, procedures and audits. At its heart are 18 safety elements which, in common with the elements of a quality assurance system, need to be understood and then complied with. SMS implementation plans were devoleped by the company's functions controlling field based activities. In order not to overburden the SMS planners, 9 priority (not the most important) elements were selected for implementation in the first year. An example extract from one of these plans is shown in figure 3.
The hidden, but possibly most important objectives of the SMS are now being realised They are to create a fresh, positive attitude in the minds of ADCO's employees, to change their perceptions from believing that safety is somebody else's responsibility to accepting it themselves, and to modify the patterns of their daily behaviour.
In the latter part of 1992 ADCO's staff worked for 2.5 million consecutive hours without accident. We believe that the SMS made a positive contribution to this ADCO record.
Application of Risk Assessment Techniques for an Additional Loading Line at Jebel Dhanna Terminal
Authors: Saadawi Hisham 
Published: December 2007

ABSTRACT
Jebel Dhanna is the only terminal for storage and export of the onshore oil production of Abu Dhabi Emirate. Crude oil flows from the tanks farm via two 48 inch gravity loading lines to the foreshore area where it is boosted by pumps to the loading berths.
The two gravity lines are needed for export at peak capacity and also for implementing the crude oil re-circulation plan in an emergency. Due to the age of the piping system, a risk assessment study was conducted to evaluate the need for a new gravity line.
Exploration and Petroleum Engineering Computing in the 90's
Authors: Al-Naji A. S. , Gaddourah M. I. 
Published: December 2007

Abstract
This paper shares Saudi ARAMCO's Exploration and Petroleum Engineering Computer Center (ECC) experience in providing the latest in computer technology to service and enhance Saudi ARAMCO's Exploration and Petroleum Engineering efforts. Saudi ARAMCO's data processing requirements have increased dramatically over the past decade. The increase can be mainly attributed to the shift in exploration from 2D to 3D seismic data processing and the growth in the number of cells and complexity of reservoir models. To fulfill these requirements, Saudi ARAMCO has established state-of-the-art computing facilities with supercomputers and highend workstations along with their sophisticated graphical plotting devices all connected through a powerful network. The high-end workstations are utilized for interactive processing and visualization of data both in seismic processing and reservoir simulation. ECC has also expanded the throughput of the network to handle the explosion of data transfer and promote the integration and effective utilization between the user friendly interface of the workstation and the intensive number crunching capability of the supercomputers.
Flexible Gridding Techniques for Coning Studies in Vertical and Horizontal Wells
Authors: Consonni Pietro , Thiele M. R. , Palagi C. L. , Aziz Khalid 
Published: December 2007

Abstract
The numerical study of water coning requires an accurate spatial discretization around the wells which may lead to a large number of grid blocks. Local refinement is therefore desired since it allows for a coarse underlying grid without loosing numerical resolution around the wells. This paper investigates the applicability of flexible gridding to study coning in both vertical and horizontal wells. These techniques can also be used for multiwell, full field coning studies.
A simple sector geometry including a producer and an injector is used. A two step approach is then followed: in the first case, it is assumed that the effects of heterogeneities are negligible and average petrophysical properties are used. In the second part, the heterogeneity of the system is also considered. For both cases, a fine grid simulation on the entire domain is used as the reference response. Various areal hybrid geometries around the producer are then investigated and their response is compared with the reference cases. For the vertical producer, the hybrid geometries are based on a coarse Cartesian grid with either a cylindrical or a Cartesian refinement around the well. For the horizontal producer only an areal Cartesian refinement is considered. In this case though, the hybrid geometry becomes particularly interesting for wells that are not aligned with the overall Cartesian grid. For these cases, the hybrid gridding techniques allow a local Cartesian refinement that is aligned with the well.
For ail cases investigated, the fine grid results can be reproduced by the hybrid geometries provided that an adequate vertical discretization is used. For both vertical and horizontal producers, the various responses suggest that grid refinement is more important than its geometry.
Prediction and Evaluation of Horizontal Well Performance
Authors: Sherrard D. W. 
Published: December 2007

ABSTRACT
Drilling and completing horizontal wells has become almost commonplace in many areas where the petroleum industry operates today. Perhaps the main obstacle to greater utilisation of the technology is confidence in accurately predicting horizontal well performance.
This paper focuses on a relatively early horizontal well program in Alaska, beginning with expectations and analyses prior to drilling, through to extensive efforts to understand well performance once on production. Evaluation of well performance is considered through well testing, production logging, and reservoir simulation. Seven years of field production data are used to compare against pre-drilling forecasts.
The review concludes that accurate reservoir description is critical to successful forecasting; simplistic description can lead to over estimates of productivity. Furthermore modem reservoir characterisation techniques may be necessary to utilise a complex description properly in predictive mode. Production logging is highlighted as a critical diagnostic tool despite the need to run on coiled tubing whereas pressure transient analysis, for which theory is well developed, can be problematic and may require modification to traditional field practices.