bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dewpoint Pressure Model for Gas Condensate Reservoirs Based on Genetic Programming
Authors: Shokir Eissa M. El-M. 
Published: June 2008

Abstract
Successful prediction of the future performance of condensate reservoirs requires accurate values of dew point pressures of the interesting reservoirs. Although the dew point pressure can be determined experimentally from collected laboratory samples, these measurements are frequently not available. In these cases, fluid reservoir properties are determined with the use of empirical correlations or determined iteratively using an equation of state (EOS).
The objective of this paper is to present an application of genetic programming (GP)-Orthogonal Least Squares algorithm (OLS) to generate linear-in-parameters dew point pressure model represented by tree structures. The GP-OLS based gas condensate reservoir dew point pressure model was generated as a function of reservoir fluid composition (in terms of mol fractions of methane through heptanes-plus, nitrogen, carbon dioxide, and hydrogen sulphide, and the molecular weight of the heptanes-plus fraction), and reservoir temperature. The new model was developed using experimentally measurements of 245 gas condensate systems covering a wide range of gas properties and reservoir temperatures. One hundred-thirty five gas condensate systems that not introduced in building the new model were used to test and validate it against the other early published correlations. The validity test shows that the new model is more accurate than the other tested correlations, whereas the new model has the lowest average absolute relative error. Therefore, the new model can be considered an alternative method to estimate the dew point pressure when the experimentally measurement is not available.
Gas Well Optimization: A Surface Roughness Approach
Authors: Farshad F. F. , Rieke H. H. 
Published: June 2008

Abstract
Gas Well Optimization implementations in the petroleum industry is taking on an important challenge as our industry moves into new frontier production areas such as deep water development and re-invigorated improved recovery operations in producing and abandon reservoirs. Today, high oil and natural gas prices dominate the energy fuels market, forcing companies to look into technologies that will efficiently produce and transport oil and gas to their customers. Attention to pipe performance in the recent past relied on conventional design values such as pipe strength parameters. The introduction of probabilistic evaluation of Oil Country Tubular Goods (OGCT) in the 1990s has provided a more focused approach to tubular strength design. Presently, strength optimization is not the only most cost-effective design concern. Current piping design is more concerned with the ability of pipes to transport fluids at a substantial reduced drag. This resistance to flow is caused mainly by inherent surface roughness due to pipe fabrication and/or corrosion products. A significant outcome in the reduction of surface roughness in pipes can help in optimizing deliverability of the production system. An application of a successful flow assurance program is the result of engineering and scientific knowledge integration, technological know-how, staff proficiency, and operability.
Our results are based on impact of surface roughness reduction as a result of utilizing internally coated pipes and newly developed alloys used in OCTG. Our approach to estimate the average surface roughness for modern pipes is based on using our new relative roughness tables and a graph (Farshad et al., 2006) in computer models showed a decrease in the pressure drop with an accompanying increase in the fluid throughput. The presenting case histories using the newly developed surface roughness values for internally coated and newly developed alloyed piping are discussed.
Computer models were used to apply the newly developed surface roughness graph and its application to simulate production results for two producing gas wells. Case histories are presented for the two gas wells located offshore Louisiana. TOPS and PIPEPHASE® 7.2 computer models were used to investigate the impact of changing the internal surface roughness of the tubing on production-performance (Simsci, 1999). Modeling results from one of the two Gulf of Mexico gas wells using different well production scenarios showed that gas flow rates increased by 24.5% when substituting a proprietary modified epoxy coated plastic tubing, and a 14.06% increase in flow rates for proprietary liquid phenolic coated production tubing over traditional bare carbon steel pipe. It is apparent that these results justify departure from existing pipe design practices.
Controlling Environmental Noise From Coalbed Methane Operations
Authors: DeGagne David C. , Burke Donald 
Published: June 2008

Abstract
A significant challenge for Coal Bed Methane producers is dealing with the impacts of high density development needed to effectively recover the natural gas resource. One such concern is the need to meet regulatory requirements for environmental noise as stated in the Energy Resources Conservation Board (ERCB) Directive 038: Noise Control (ERCB Directive 038) and Colorado Oil and Gas Conservation Commission (COGC) Aesthetic& Noise Control Regulations, Series 800 (COGCC Noise Regulations). Anyone who has ever been involved in the process of complying with regulatory noise standards will agree that it is a complex and challenging task. Some regulated companies struggle through this process often dealing with unfamiliar considerations such as trying to predict facility noise levels before it is even built, or gambling on a best guess as to what is the right, least expensive amount of noise mitigation needed to meet regulatory requirements for environmental and occupational noise. Even the best of intentioned operators fail to hit the mark, sometimes by wide margins and end up with a situation that is potentially worse than when they started. No company wants to go through a process where in the end a lot of time, resources, and public confidence have been lost not to mention now being in a regulatory non-compliant status.
This paper will elucidate valuable lessons & experience learned and case histories for the successful approach to noise solutions accepted by regulatory agencies and industry clients. In addition to discussing the complexities of acoustical engineering practices this presentation will also cover the most significant points of ERCB Directive 038 and COGCC Noise Regulations.
Applicability of the Arps Rate-Time Relationships for Evaluating Decline Behavior and Ultimate Gas Recovery of Coalbed Methane Wells
Authors: Rushing J. A. , Perego A. D. , Blasingame T. A. 
Published: June 2008

Abstract
This paper presents results of a simulation study designed to evaluate the applicability of Arps’ [1945] decline curve methodology for assessing reserves in coalbed methane reservoirs. We simulated various coal properties and well/operational conditions to determine their impact on the production decline behavior as quantified by the Arps decline curve exponent, b. We then evaluated the simulated production with Arps’ rate-time equations at specific time periods during the well's production decline period and compared estimated reserves to the "true" value (defined in this paper as the 30-year cumulative production volume). To satisfy requirements for using Arps’ models, all simulations were conducted using a constant bottomhole flowing pressure condition in the wellbore.
The significant results from our study include:
All of the computed values of the long-term decline exponents were within the limits originally defined by Arps, i.e., 0.0 ≤ b ≤ 1.0. Agreement between Arps’ recommended b-exponent range and our results using simulated performance data also suggests that, if applied under the correct conditions, the Arps rate-time models are appropriate for assessing reserves in coalbed methane reservoirs; The Arps b-exponents were not constant during the production decline period. For many simulated cases, the early decline behavior (within a few years after reaching the peak production rate) appeared to have exponential decline but eventually became more hyperbolic later in the well's life. Use of Arps’ exponential model early in the production history in those wells with long-term hyperbolic decline behavior tended to underestimate gas reserves; The largest reserve estimate errors typically occurred during the first few years after reaching the peak production rate and during the initial production decline period. For those wells exhibiting long-term hyperbolic behavior, the initial reserve estimate errors underestimated reserves by as much as 20 to 30 percent; Heterogeneities in coal properties cause the production declines to deviate from exponential to hyperbolic. Properties having the largest impact on the production decline behavior include the shape of the adsorption isotherm, cleat permeability anisotropies, the shape of cleat gas-water relative permeability curves, stress-dependent cleat permeability and porosity, and layered coal seams with differences in initial reservoir pressures; We also observed a strong influence of well flowing pressure conditions as modeled with a bottomhole flowing pressure constraint. For all other properties and conditions being equal, wells with lower bottomhole flowing pressures exhibited more long-term hyperbolic behavior as defined by higher Arps b-exponents.
A New Approach to Improve the Phase Behavior of Supercritical Hydrocarbons Using PR EOS
Authors: Faradonbeh M. Rabiei , Bahramian A. , Masoudi R. 
Published: June 2008

Abstract
Reliable predictions in compositional reservoir simulators require a proper equation of state to describe accurately the phase behavior of fluids both in sub/super-critical regions. In miscible processes such as CO2 and lean gas injections, the injected fluid is usually at it's super-critical temperature, and therefore the current forms of EOS might not be suitable, since their temperature-dependency term (Alpha Function) have been obtained using experimental data of pure components at sub-critical regions. The same problem exists for compositional simulation of gas condensate reservoirs in which the major components are above critical temperature.
A new alpha function was developed using sound velocity data of pure components at their super-critical temperatures, since sound data can be measured accurately at large temperature range. Sound velocity can be thermodynamically related to the EOS parameters. An appropriate form of alpha function has been hence obtained for each component at super-critical temperatures.
In this work, the sound velocity experimental data of pure methane, ethane, propane and carbon dioxide has been used to generate a new form of alpha function at super-critical temperatures using PR EOS. The new function was then tested and validated against different experimental data from binary, ternary and multi-component systems and was found satisfactory in improving the prediction results.
By adapting the new methodology and developing the new alpha function for other components at super-critical region, it diminishes the need for temperature-dependent BIPs and also decreases the task for tuning of a given EOS against experimental data.
Estimating Water Production Behavior from Edgewater Drive in a Monocline Reservoir
Authors: Ayeni Kolawole , Wattenbarger R. A. , Maggard J. B. 
Published: June 2008

Abstract
It is often important to predict water production performance of oil wells early in, or maybe before, their production life. Some of the challenges encountered include difficulty in predicting water breakthrough time and post breakthrough performance. The case considered here is a well producing from a monocline with an edge-water aquifer. Although such problems can be computed with reservoir simulation, the objective of this work was to develop simple empirical correlations for predicting water production behavior from a monocline reservoir.
The reservoir model was described as a single well producing from the top of a monocline drainage block with water drive from an infinite-acting aquifer. During the reservoir simulation runs, water would cusp and cone into the well, increasing water production and decreasing oil production. A number of simulation runs were made, varying eleven model variables. Typical model variables include dip angle, formation thickness, production rate, etc. For each run, a modified Addington-style13 plot was made. The relationship between each model parameters and three graphical variables was used to develop the set of empirical correlations. The empirical correlations developed were integrated with some derived equations that relate important reservoir parameters and incorporated into a computer program.
The developed correlations and program can be used to carry out sensitivity analysis to evaluate various scenarios at the early planning stages when available reservoir data are limited. This gives a quick and easy method for forecasting production performance with an active edge-water drive. Furthermore, the approach developed in this work can be applied to water production problems encountered in other field/reservoir.
Increased Oil Production by Unconventional Wells—Short-Radius, Horizontal, and Multilateral in the Hassi Messaoud: Thick Multilayer Cambrian Formation, Algeria
Authors: Youcef Boughaba , Tiab Djebbar 
Published: June 2008

Abstract
Unconventional drilling technology has been widely and successfully applied around the world for the recovery of Hydrocarbons. Significant technological achievements have been made in horizontal technology through a variety of innovations in tools, and experience gained over the past years.
Unconventional drilling provides solutions to the recovery of oil from inaccessible areas in reservoirs such as un-drained fault blocks, marginal fields, production improvement in tight reservoirs, intercepting natural fractures that cannot be accessed to their full potential with vertical technology and/or improvement of water-flood sweep efficiency, etc. In case of forced abandoning of highly productive vertical wells, the existing well bores can be reentered and horizontally re-drilled through the pay zone, primary objective being, increasing the well bore contact with one or more reservoirs.
One of the most important issues affecting economics, especially of re-entries, is whether the production enhancement will consist of accelerated production, increased reserves, or both. For a well with accelerated production only, net worth is improved, although total revenue is not increased. An increase in reserves is important to the economic success of a horizontal re-entry program.
This paper discusses performance review of unconventional wells in Hassi Messaoud including selection of target reservoir, planning options, well testing methodologies,well completions, specific reservoir response, and production management Complex reservoir response poses a challenge for us in identifying flow behavior in the horizontal bore hole, flow regimes in the reservoir, flow mechanisms during well testing, and during vertical lift.
This research is an attempt to meet such challenges and involves analyzing the actual field data to identify the potential response of highly complex reservoir system to the unconventional wells. Flow regime and flow pattern identification is duly supported by flow equations with modification related for Hassi Messaoud Field.
Use of Hydrajet Perforating to Improve Fracturing Success Sees Global Expansion
Authors: McDaniel B. W. , Surjaatmadja Jim B. , East Loyd E. 
Published: June 2008

AbstractAs shown by technical papers as early as the 1960s, our industry has long known that hydrajetting perforations or slots through cemented casing could often "bail-out" a problem well that otherwise seemed completely resistant to hydraulic fracturing attempts. For most of the first 50 years of fracturing applications, few operators had sufficient demand for the fracturing process to make it a commodity service, especially before the advent of coiled tubing (CT) services in the 1980s. Often, this type of well service was costly because of the need for both abrasive mixing and high-pressure pumping. In many cases, it was too time consuming to be practical as an "every-well" application, and lower-cost conventional explosive shape- charge perforating seemed sufficient for most wells.As oil and gas prices have drastically increased in recent years, many operators have realized that for some well conditions, the use of hydrajet perforating (HP) can improve fracture stimulation efficiency and well economics. In a few cases HP has proven to be the only way that effective fracture stimulation could be achieved. In the past few years there has been a growing acceptance among both operators and service companies that hydrajet (abrasive jetting) perforating can improve overall well economics for fracture stimulated wells in many reservoirs. Some newer methodologies have combined hydrajet perforating and hydraulic fracturing into a single, continuous, multi-stage stimulation method. For many wells needing multiple fracture stimulations, significant reductions in nonproductive time (NPT) allows for reduced well costs even when more actual fracture stages are pumped. Use of more stages has often provided significant production gains and greater recoverable reserves.Enhanced stimulation success in many moderately hard and very hard formations have proven the value of converting from shape charge perforating to hydrajetting as a stand-alone operation to avoid severe near-wellbore problems during hydraulic fracturing stimulation treatments. Since about 2000, and especially during the most recent 5 years, service providers have progressively expanded the processes, which included hydrajet perforating, especially in conjunction with hydraulic fracturing methods. This paper will review the expanding applications of hydrajet perforating in recent years, including case histories from several global applications.
Geothermal Reservoirs: A Renewable Source of Energy and an Extension of Petroleum Engineering
Authors: Ullah Syed Zahoor , Bukhari Syed Rehan Shah 
Published: June 2008

Abstract
With the concern over anthropogenic climate change (i.e. man-made climate change), there is a growing awareness that we must utilize energy resources that are sustainable. The power obtained from geothermal reservoir is one such sustainable resource that has the potential to supplement our energy systems and to displace many conventional fuels. In contrast to many renewable technologies, such as wind or solar, the geothermal resource can be used 24 hours a day, 7 days a week without any harm to the environment.
It is due to this reason that geothermal development, a natural extension of oil and gas development activities, is attracting both new petroleum engineering graduates and established petroleum engineers in increasing numbers. Along with the importance of geothermal energy, this paper details as to how different phases of geothermal industry like drilling, production, and reservoir utilize petroleum engineering techniques, the challenge awaiting engineers as they work to solve first- time problems and improve technology for future activities. The geothermal industry has tremendous potential for growth and will make a significant contribution to worldwide energy supplies.
Test Method to Optimize Acid-Soluble Cement for Unconventional Gas Completions
Authors: Luke K. , Soucy K. 
Published: June 2008

Abstract
In recent developments of unconventional gas reservoirs, there has been a move towards drilling horizontally to increase formation contact with the objective to increase production. A longer horizontal extension gives greater formation contact. However, these extended laterals must be cemented which has caused constraints on optimal reservoir production. Studies have indicated that conventional cements are one of the primary causes resulting in reduced fracture initiation.
Acid-soluble cements have been advocated for use in unconventional gas reservoirs as a means to reduce the rate of inefficient fracture initiations. The logic behind using acid-soluble cement was based on field study examinations completed in 2005. These studies indicated that more than 25% of cemented horizontal laterals experienced fracture initiation problems compared to 4% for uncemented horizontal laterals. In acidizing acid-soluble cement in the area of strategically placed clusters, conditions approaching open hole are obtained similar to that of uncemented horizontal laterals. Cement remaining between clusters provides sufficient zonal isolation for well bore stability.
There are no standard tests to define the characteristics of acid-soluble cements such as acid solubility or rate of dissolution that are factors crucial to obtaining good cement removal and minimal near well-bore issues. In this context a prototype test method has been developed to more closely simulate dissolution of acid-soluble cement for unconventional gas reservoir applications. Data obtained indicate the benefits of such a method to define the most appropriate acid-soluble cements, acid treatments and develop improved systems.
Published test parameters vary considerably and given the number of variables involved in dissolution techniques there is a question as to what defines a good acid-soluble cement. Development of a test method that simulates down hole conditions provides a tool to design acid-soluble cement systems to optimize open hole around perforations and ultimately minimize fracture initiation problems.
Investigation of Water-Swelling Packers
Authors: Al-Yami A. S. , Nasr-El-Din H. A. , Al-Arfaj M. K. , Al-Saleh S. H. , Al-Humaidi A. S. , Awang M. Z. , Al-Mohanna K. S. 
Published: June 2008

Abstract
Achieving successful zonal isolation during well completion is critical to minimize early water production. Currently, cementing is the only method used in Saudi fields to provide zonal isolation. However, in horizontal sections, cementing becomes a challenge and water flows can occur due to channeling. Another method for zonal isolation is to use a rubber elastomer bonded onto a base pipe. The rubber swells in water and provides a seal between the base pipe and the open hole.
This paper will outline the step-by-step qualification testing that was carried out in Saudi Aramco facilities in an attempt to improve zonal isolation in horizontal and multilaterals wells.
In this study, we present lab evaluation of elastomers at 190°F using brines of different ionic strengths and pH values. The evaluation involved examining the effect of salinity and pH on the rate of swelling of elastomers. Also, the study investigated the effect of 15 wt% HCl acid on the swelled elastomers. To the best of the authors' knowledge, no previous work was done to examine the impact of these factors on the swelling mechanisms.
The elastomer bonded in pipes was tested in autoclaves. The pressure drop across the pipes was measured as a function of time. The influences of fluid density and viscosity were also investigated using elastomer samples. Swelling was related to volume of the samples and fluid characterstics.
Water swelling elastomers withstand pressures up to 5,000 psi at 190°F after placing the elastomers in salinities up to 200,000 mg/l. However, the swelled elastomers shrink in 15 wt% HCl. This paper discusses the advantages and limitations of swelling elastomers and gives recommendations for successful field applications.