bluuebunny/crossref_metadata_2025_split huggingface dataset:
Modeling and Measuring Dynamic Well Intervention Stack Stress
Authors: Smalley E. , Newman K. , Stephens R. 
Published: December 2007

Abstract
This paper reports the field results obtained from application of a system that provides both pre-job modeling capabilities and real-time monitoring of maximum stress levels in the entire intervention stack, from the wellhead to the injector assembly. In addition, the paper documents the dynamic movement capabilities recently incorporated in the model and validation of the model calculations.
Frac Packing with Low Environmental Impact Hydraulic Fracturing Fluid Benefits the Operator
Authors: Baycroft P. D. , McElfresh P. M. , Crews J. B. , Spies B. , Wilson B. , Conrad M. , Blackman M. 
Published: December 2007

Abstract
Offshore operators and service companies are increasing concerned about the environmental aspects of their offshore operations. Many offshore completions utilize "frac packing" as a preferred method to complete the soft formations found in the Gulf of Mexico. The frac pack operation manufactures and pumps large volumes of stimulation fluids from the fracturing stimulation vessel into the well. Most operations require at least two work string volumes of fracturing fluid to be reversed out and disposed of. This paper presents the development of a hydraulic fracturing fluid that not only met the oil and grease criteria established for well treatment fluids, completion and workover fluids; but how it was developed to meet the tighter standard established for the discharge of water based drilling fluids to comply not only with the letter of the regulations but with the spirit of the regulations.
The service company specifications for the development of the low environmental impact fracturing fluid required not only it meet the oil and grease standard but also the toxicity standard for water based drilling mud and a biodegradability standard. The fluid development required it to meet the more stringent environmental standard, maintain its performance as a fracturing fluid and remain price competitive. The research process, the sourcing of new suppliers and the development of unique chemistry, with new patents, to accomplish the fluid development objectives are presented.
The environmental performance of the fluid saves disposal costs, minimizes well site logistics and reduces risks associated of an accidental spill to both the operator and Service Company. A case history of the use of the fluid in an environmentally sensitive area is discussed and how the low environmental impact fracturing fluid system enabled the operator to discharge the fluid saving on disposal costs.
Investigating Applicability of Vogel's IPR for Fractured Wells
Authors: Rueda J. I. , Zakharov A. , Mach J. 
Published: December 2007

Abstract
It is a common practice in the oil industry that production engineers use Vogel's correlation to correct the IPR curve below the bubble pressure for unfractured and fractured wells. However, there has not been a comprehensive investigation to ensure if the Vogel's correlation can be applied for fractured wells.
This paper presents a new correlation to build IPR curves or predict production performance below the bubble pressure for fractured wells. In order to investigate fractured well performance below bubble point, about 1,000 simulations runs were performed using well-refined size grid for several sets of relative permeability curves and PVT data. The simulation model has been validated against analytical solution. Those runs cover a big practical range of fracture penetration 0.1 to 1.0 and dimensionless fracture conductivities from 0.5 to 50. Steady state conditions were analyzed at this study. All the mechanisms that cause the difference between fractured well and radial flow performance below the bubble pressure has been also well studied and will be presented in this paper.
It was found that Vogel's correlation underestimates fractured well performance below bubble point. Vogel suggests a correction of AOF by 45% meanwhile the simulation results and new correlation show that the correction should be only 22%. Therefore, engineer could have an error of 43% using Vogel for estimating AOF for a fractured well.
Another finding of this study is that multiphase effect is dependent on fracture conductivity and almost independent on fracture penetration. Higher conductivity fractures has bigger gas banks therefore they are affected by multi-phase effect to greater extent than lower conductivity ones. The new correlation is now being used for different fields and better fits the data than Vogel's correlation.
Impact of Completion Fluids on Productivity in Gas/Condensate Reservoirs
Authors: Al-Anazi H. A. , Okasha T. M. , Haas M. D. , Ginest N. H. , Al-Faifi M. G. 
Published: December 2007

Abstract
Gas wells in tight reservoirs have shown low gas deliverability after drilling and completion operations. This is partially attributed to penetration of completion fluids into the near the wellbore. This increase of liquid saturation into the reservoir can play a significant role in the blocking of tight rock due to high capillary forces and vapor pressure. The scope of this study was to investigate the impact of completion fluids on gas productivity in carbonate and sandstone reservoirs, and to evaluate feasibility of using various solvents to remove and/or minimize liquid blocking effects. In this study, extensive coreflood experiments were conducted on carbonate and sandstone cores recovered from gas reservoirs in Saudi Arabia to assess the loss in gas relative permeability caused by several fluids used as completion fluids. Alcohols were also evaluated as solvents to remove or minimize water blockage. Interfacial tension of fluids was measured using the pendent drop method at reservoir conditions. Experimental results showed that the used completion fluids (brines, KCl, alcoholic brines, and diesel) caused a severe reduction in gas productivity. The clean-up of these fluids was found to be a very slow process and is a function of capillary forces. Neat diesel caused a decline in the gas productivity index (PI) more than brine because it has a lower mobility. The solvents used were effective in displacing the completion fluids studied and consequently restoring gas productivity. Mixing brine with alcohol speedup the cleanup of trapped liquids.
Measurement of In-Situ Cuttings Concentrations Using Nuclear Densitometers in a Horizontal Annulus at Simulated Downhole Conditions
Authors: Zhou L. , Ahmed R. M. , Miska S. Z. , Takach N. E. , Yu M. , Pickell M. B. 
Published: December 2007

Abstract
This study presents experimental results and techniques that are developed for measuring in-situ cuttings concentration using nuclear densitometers under dynamic conditions. One of the key problems in borehole hydraulics and cuttings transport is the determination of in-situ cuttings concentration in the borehole while drilling. In order to investigate cuttings transport efficiency with aerated fluids under elevated pressure and temperature conditions, in-situ cuttings concentrations were measured manually (i.e. by flushing out the cuttings into a container and weighing them) and using nuclear densitometers. In-situ cuttings concentrations that were obtained using these two different measuring methods are compared and discussed. The results show good agreement between densitometer readings and cuttings weight measurements. This study is useful for designing in-line monitoring systems that accurately measure the cuttings concentration in drilling applications.
Stripper Gas-Well Production-Optimization and Reserve Retention
Authors: Gaskill Robert A. 
Published: December 2007

Abstract
The Effect of gas-water content phase behavior on mature methane rich gas wells has been investigated and found to be extremely detrimental. The wells performance becomes stressed and ultimate operating reserves will deviate negatively to previously established developed reserves due to fluid loading. The fluid loading phenomenon is usually associated with a gas production rate falling below the minimum mist flow rate required for the existing wells, producing tubular geometry. This analysis presents a method to reverse the ill effects of down hole phase behavior and suggest an alternate lift option. The advantage of this method is that it normally requires little or no down hole reconfiguration, and successful application would be superior to current artificial fluid lift operations. The resultant would translate to restoration or original developed reserves and quite possibly enhance production rate.

Scenario
It is only recently within the oil and gas industry history, that the concept of stripper gas well production has been recognized and addressed. The enhancement and retention of natural gas production has largely been secondary or non-existent compared to the new technologies directed toward the development of advanced oil recovery techniques. However, the future of natural gas has rocketed to the forefront of valued energy commodities. This is a result of its continued and prolific trend increase in demand. Natural gas has become the environmentally preferred fuel to meet future domestic power requirements. The efficient production and protection of established reserves has become of paramount value and importance in the light of national energy security and economic interests. Industry and attendant governmental agencies are now working in concert to address this issue and have successfully supported new and improved lifting technology.

Problem
A detrimental phenomenon exists within dry methane rich gas areas. That is, those natural gas reservoirs that might be described as low water saturation and devoid of any free water, or liquid hydrocarbon production throughout their early life. Mature production, invariably, commences to show signs of fluid loading. Hence, an operator will make attempts to counteract this performance by some mechanical adjustments. Pumping units, plunger lifts, downsized tubular, down-hole separators and soap sticks, are some of the common response strategies. All may off temporary, but not necessarily sustained relief. The operator's ultimate inability to cope with this phenomenon, however, usually results in the premature abandonment of the individual well and loss of developed gas reserves.
Improved Permeability Equation From the Bundle-of-Leaky-Capillary-Tubes Model
Authors: Civan F. 
Published: December 2007

Abstract
There is no consensus about the proper theory and equation of permeability of porous media in spite of the numerous investigations conducted to date. Many different expressions have been proposed in the literature for permeability prediction and/or correlation. The presently available and frequently used models, including the popular Kozeny-Carman equation, have certain limitations and are inadequate for applications involving the geological porous media. The bottom-line question is just what is the equation of permeability of the geological porous formations?
This paper provides some insights into the relationship of the porosity and permeability. The bundle of leaky capillary hydraulic tubes with cross-flow model of porous media by Civan1-7 is shown to alleviate the deficiencies of the present models. This model adequately approximates the actual flow schemes in porous media because it allows for interactions between the capillary hydraulic paths. The porosity-permeability data of various core samples are analyzed with this model. It is demonstrated that the power law exponent of the leaky-tube model deviates significantly from the unity. Therefore, the Kozeny-Carman8-9 equation having a constant exponent of unity cannot describe such core data.
Rheology and Hydraulics of Polymer (HEC) Based Drilling Foams at Ambient Temperature Conditions
Authors: Chen Z. , Ahmed R. M. , Miska S. Z. , Takach N. E. , Yu M. , Pickell M. B. 
Published: December 2007

Abstract
An experimental investigation on polymer-based drilling foams was carried out. Rheology tests were performed with foams that have different concentrations of Hydroxylethylcellulose (HEC) and 1% commercial surfactant. Experiments were conducted in a large-scale flow loop that permits foam flow through 2", 3" and 4" pipe sections, and a 6"×3.5" annular section. During the experiments, frictional pressure losses across the pipe and annular sections were measured for different gas/liquid flow rates, polymer concentrations (0%, 0.25% and 0.5%) and foam qualities (70%, 80% and 90%). Significant rheological variations were observed between aqueous foams containing no polymers and polymer-thickened foams.
Experimental data show three distinct flow curves for the 2", 3" and 4" pipe sections, which indicates the presence of wall slip. The Oldroyd-Jastrzebski approach was used to calculate the wall slip velocity and determine the true shear rate. It has been found that wall slip decreases as the foam quality or polymer concentration increases. Two foam hydraulic models, which use slip-corrected and slip-uncorrected rheological parameters, have been proposed. These models are applicable for predicting pressure loss in pipes and annuli. Model predictions for the annular test section are compared with the measured data. A satisfactory agreement between the model predictions and measured data is obtained. This paper will help to better design foam drilling and cleanup operations.
Federal Lands Access Inventories Conducted Under the Energy Policy and Conservation Act (EPCA) Amendments of 2000
Authors: Watson R. L. 
Published: December 2007

Abstract
The availability of onshore Federal lands for oil and gas exploration and production is the subject of a polarized debate. Industry interests claim that an excessive amount of Federal land is locked up; environmental interests assert that almost all the public lands are available for oil and gas leasing with few restrictions. The EPCA inventory represents an effort to supply a quantitative assessment of the situation.
Should Horizontal Sections be Cemented and how to Maximize Value
Authors: Ilseng J. R. , Hoskins L. R. , Matthews H. L. , Fuller G. A. , Pronger D. , Ravi K. 
Published: December 2007

Abstract
Development of marginal fields offers unique challenges during drilling, completion, stimulation, and production. The underlying objective should be to maximize the value of the field over its productive lifetime. Every phase of the well construction needs to be fully evaluated for subsequent impact on the safety and economics of producing oil and gas from the field. Log evaluation of formation type, thickness, and characteristics may determine the final completion plan, although lack of natural barriers from close water contact may be of major concern when a large stimulation program is required. Specialized low-density cementing systems may be necessary for maintaining satisfactory equivalent circulating density (ECD) for coverage across weak formations. These low-density systems can be prepared either by an engineered foaming operation or by the use of specialized additives blended with cement to lower the density, but production quality properties should be maintained. Consideration should also be given to the final cement sheath properties, which can provide isolation for the "life of well" following cyclic pressure loading from stimulation, testing, and flowing phases.
This paper addresses the advantages and disadvantages of the historical approach to constructing and producing horizontals. Completion processes and procedures with emphasis on cementation designs and best practices for horizontal casing are presented with major focus on resulting production rates. These case histories will cover both cemented and uncemented producing wells. Also included will be new methods for predicting cement failure modes as a result of cyclic pressure loading from stimulation jobs. Recent design procedures and ensuing effect for maximum value of the producing asset for life of the field will be compared with historical procedures.
A Unified Approach for the Removal of Barium Sulfate Scale Using Coiled Tubing
Authors: Boudreaux C. D. , Falk K. 
Published: December 2007

Abstract
Removal of scale depositions from wellbore tubulars has always posed a challenge to operators. Traditional methods to do so have included chemical treatments, mechanical methods, or even removal of affected tubulars. All of these methods have varying degrees of success, as well as varying cost to operators depending on the type and amount of deposition in the tubulars.
Barium Sulfate scale removal has traditionally posed the greatest challenge to operators and service companies alike. Chemical soaks have been developed and applied as well as mechanical methods, usually meeting with limited success. As a result of these failures, a dependable, engineered and cost effective approach has been developed. The process combines the use of traditional coiled tubing operations and a high-pressure rotary jetting tool to remove the Barium Sulfate scale – without use of solvents. The process has been successfully utilized to completely remove over 9,000’ of Barium Sulfate scale in subject wells that have not been effectively cleaned when tradition methods have been tried.
This paper will look at well conditions conducive to the formation of barium sulfate scale, as well as why it is such a difficult material to remove. Coiled tubing solutions will be discussed, culminating in a collection of case histories where a unified mechanical / jetting program has had best results.
Constructed Treatment Wetland Plant Monitoring Parameters
Authors: Myers J. E. , Nijhawan N. 
Published: December 2007

Abstract
When testing and evaluating constructed treatment wetland (CTW) performance, there is a tendency to focus on monitoring parameters for wastewater kinetics to meet discharge limits or water re-use standards, while the plant monitoring parameters (metrics) are neglected. This paper identifies six useful plant metrics, describes the plant monitoring methods, relates the parameters to CTW performance and assessment, and provides typical value ranges for parameters of plants commonly used in CTWs. Plant data are from pilot and full-scale CTWs, natural wetlands, and literature.
Don't Break the Wellhead
Authors: Portman L. , Crabtree A. 
Published: December 2007

Abstract
Drilling and workover rigs use a drawworks to pull up on the tubulars deployed into a well. The drawworks is attached to a mast or derrick, which in turn is supported by the ground or a floating vessel. The tubular's weight is not transferred to the wellhead.
Coiled Tubing uses an injector head, instead of a drawworks, to pull and push tubing in and out of a well. The injector is generally mounted directly onto the wellhead, unavoidably transferring some of the reactive loads to the wellhead.
These loads can be very substantial. They not only include the tubing's weight in the well but also loads generated by the Coiled Tubing on surface, that tubing which is being bent and pulled sideways. Often additional support is required to at least partially isolate these loads from the wellhead. This paper identifies the various loads that Coiled Tubing imparts to a wellhead and how support mechanisms provide protection to the wellhead.
Critical Analysis of Exploratory Wells in a New Field Development in Trinidad and Tobago
Authors: Dwarkah D. R. , Boodoo C. S. , Rajnauth J. J. , Seecharan K. 
Published: December 2007

Abstract
This paper seeks to identify the causes and relative magnitudes of wellbore stability problems in a recently discovered, highly faulted field in Trinidad and Tobago. The two main factors that have been identified are reactive shales and tectonically stressed formations, which result in wellbore caving and seepage losses of mud under static conditions. Our data set includes every well drilled in the field to date. In order to determine whether problems are wholly formation related or are in part caused by drilling parameters, the following were analysed: Rate of penetration per day in the formation of interest. This data was used to determine if wellbore cleaning problems were associated with high rates of penetration. Models for wellbore cleaning employed ranged from the simplistic CCI model to the more advanced service company methods. Parameters such as pump rates were inherently a part of this assessment.Caliper logs to assess the degree of washouts in formations of interest.Mudlogging data to identify the degree to which formation problems are tectonic or chemical in origin.Comparison of mud type used in all wells to drill formations of interest in order to determine its relevance to the problem.Assessment of bit type used in an effort to find out whether there was a higher low gravity solids (LGS) content in the mud with one or other bit type. This influences the hole cleaning properties of mud such as PV and YP.
This paper documents a potential solution to the problems identified and details the drilling history of an exploratory well in a field where these conditions apply.
It is hoped that the results of analysis presented in this paper will provide guidance for future exploration and appraisal programmes on the east coast of Trinidad.
Third-Party Verification of a Company-wide Inventory System under the New ISAE 3000 Assurance Standard
Authors: Nordrum S. , Cain J. , Lee A. , Eddis M. , Woo C. M. , Shires T. , Campbell L. 
Published: December 2007

Abstract
Having completed its first post-merger greenhouse gas (GHG) emissions inventory in 2002, ChevronTexaco engaged KPMG LLP (UK) and URS Corporation to perform an independent review of the GHG data quality for both 2002 and 2003. A key objective was to enable ChevronTexaco to set GHG emissions goals with the assurance that the goals are based on sound and robust baseline data. The verification exercise also demonstrated the company's clear commitment to action on the climate change issue by implementing and verifying an enterprise-wide GHG emissions inventory. KPMG and URS conducted a phased approach to the verification process. Phase 1 consisted primarily of system, process and protocol reviews at the corporate level, and Phase 2 focused on system and process reviews at the business unit level. The third party verification process helped ChevronTexaco to more fully understand the challenges of reporting reliable GHG data. This paper presents the results of and key learnings from the third-party verification effort.