bluuebunny/crossref_metadata_2025_split huggingface dataset:
Case History — Obtaining Unit Wide Archeological Clearance to Speed Up Federal APD Approvals
Authors: Hauck Forrest R. , Baumann Richard E. 
Published: December 2007

ABSTRACT
When an extensive amount of oil or gas exploration is projected for a homogenous area which apparently contains a low cultural resource density, a sample survey of the area can be utilized to identify and define environmental variables associated with cultural site presence. Through the implementation of a large scale sampling study, the archeologist can determine those topographic features and vegetation zones containing high to low resource density and can provide the developer with archeological clearance recommendations based upon the site sensitivity of specific environments. This procedure can reduce the need for archeological evaluations in the area by concentrating future examinations in those localities where environmental factors indicate a moderate to high potential for cultural site presence. The Archeological-Environmental Research Corporation (AERC) has successfully utilized this technique on several large areas in the overthrust belt region of northeastern Utah.
Can We Increase Both Penetration Rate and Bit Footage in Hard and Very Hard Formations
Authors: Saif Mohamed Ahmed Abou 
Published: December 2007

ABSTRACT
The author has proved in his doctor thesis1 that the 4-cone 4-nozzle insert-bit2,3 (Fig. 1), patente by the author, has superiour performance than that of the conventional 3-cone 3-nozzle insert-bit (Fig. 2) when drilling was performed both in laboratory and in the field in the same hard and very hard abrasive formations and under the same drilling conditions (weight on bit, rotary speed, and rate of flow of the same drilling fluid).
With the 4-cone insert-bit, footage drilled was more than three times that drilled with the 3-cone insert bit, while penetration rate was about two to three times that of the 3-cone insert-bit.
In the same line, this research work studied and analyized the drilling performance of the 3-cone insert-bit in hard and very hard formations and a solution to the problem "How to increase both penetration rate and bit footage in hard and very hard formations and consequently the unit drilling cost can sharply be reduced" was offered. This includes a new design concerning the distribution and the number of the inserts on the three cones of the bit.
Using Geomechanics to Optimize Field Development Strategy of Deep Gas Reservoir in Saudi Arabia
Authors: Ahmed Mahbub S. , Finkbeiner Thomas , Kannan Adnan A. 
Published: December 2007

Abstract
Saudi Aramco has embarked on drilling long horizontals and maximum reservoir contact (MRC) wells in the deep gas reservoirs. Regional stress field is playing an important role in predicting wellbore stability and future production performance of these wells. To successfully drill and produce these long horizontal wells a detailed geomechanics study and its results needed to be incorporated in the decision tree. Reservoir Management was keen to find the optimum azimuthal direction to place horizontal wells, which will minimize the risk of hole breakouts, optimize drilling mud weights, and ensure sustainable production under depletion mode. A study was undertaken to study the effect of geomechanics on drilling and production of these gas wells. Drilling and production histories along with laboratory measurements were incorporated in the study. The study concluded that horizontal wells should be drilled parallel to the locally derived maximum principal stress (SHmax) azimuth to maximize borehole stability and minimize required mud weights during drilling and production. To date a substantial number of wells have been drilled in the field following the recommended drilling direction that would ensure minimum damage to the reservoir and well's productivity.
The objective of the paper is to illustrate methodologies employed to find the optimum drilling direction causing the least damage to the reservoir and discuss implementation of its findings in the field development.
Smart Model Simplifications to Speed Up Uncertainty Analysis of Integrated Production System Models used for MT forecasting
Authors: van Zandvoord Walrick E. J. J. , Hooimeijer Martijn 
Published: December 2007

Abstract
As part of a study to reduce run times of Probablistic Forecasts iterating around complex Integrated Production System Models, several simplification options have been investigated so that probabilistic forecasts can be created in significantly less time than running many iterations around a full model.
This was achieved through smart model simplification, i.e. selected simplifications where these were expected not to hurt the results and surfacace and subsurface system dependencies.
Based on a representative field model a 35x reduction in run time was achieved. At each stage in the simplification process the results were compared with the full model and the last step was to compare the probabilistic results between the full and simplified model. The probabilistic analysis was based on a Monte Carlo simulation (Latin Hypercube).
The result of this study will help operating companies to perform uncertainty analyses on their 1-2 years forecasts based on integrated production system models, with the right level of simplification. The forecast and the uncertainties can then be used to assist in investment decisions and stakeholder management. Making the wrong forecast may be a problem, but making the wrong assessment of its uncertainties or not providing them at all could seriously affect the reputation.
A New General Formula for Dimensionless Well Inflow Performance Relationship
Authors: Haiquan Zhong , Yingchuan Li , Yulian Wen , Chengjian Li , Wei Li 
Published: December 2007

Abstract
In 1968, Vogel presented an empirical inflow performance relationship (IPR) for solution gas drive reservoirs based on numerical simulation results. However, the relationship lacks in relevant physical significance, and it does not take into account the effect of turbulence that may occur when fluids flow into the wellbore1 at high velocity. Consequently, limitations exist in the theory of deliverability forecast and its application.
Based on the nonlinear-flow mathematical model developed by Forcheimer, a dimensionless IPR for a single phase (oil or gas) is deduced. New IPR formulas for solution gas drive reservoirs as well as partial solution gas drive reservoirs are developed by recognizing the similarity of deliverability equations between linear flow and nonlinear flow of a single phase. And a general dimensionless IPR formula is gained by summing up and normalizing the IPRs in different cases, where characteristic parameters a and n have explicit physical significance. An example is given to compare the new general formula with the exponential equation and Vogel equation. The results show the new IPR formula can predict the well deliverability with high accuracy.
Research and Application on Horizontal Well Sectional Acidizing Technology
Authors: Pei Xiaohan , Zhang Yusheng , Zhang Shujin , Li Qingzhong , Ban Li , Kong Lihong , Wang Jinyou 
Published: December 2007

Abstract
Horizontal well technology is a technological revolution in oil industry, and it is one of the most important methods of thick layer sustainable production and marginal low permeable formation exploitation in Daqing Oilfield. Usually, horizontal wells will suffer damage during the course of drilling, completion and production due to the mud and other organism's pollution. Therefore, acidizing is an effective method to improve conductivity near the wellbore and enhance overall production. However, commingled acidizing cannot guarantee acid being pumped into polluted intervals uniformly owing to long horizontal length (583.7m on average) and heterogeneity formation.
A new composite acid fluid and a novel sectional acidizing technology by inject sealing ball to build the pressure to open sliding sleeves were developed to solve the problem of long interval acid placement. Composite acid system features long corrosion inhibition period, which can improve core permeability by 160% and restore the damaged core permeability by 203%. Sectional acidizing string can resists pressure up to 40MPa and temperature up to 90°C. Four stages ball injection and five intervals treatment can be done in one trip. Moreover, residual acid can be reverse flushed after acidizing.
Up to now, this technology has been applied on 5 wells (18 intervals in total) in Daqing Oilfield. Now satisfactory stimulation results have been achieved. Technical success ratio is 100%; average single well liquid production is increased by 5.2m3/d; oil production is increased by 4.5t/d; and average production enhances by 168%.
Integrated Wellbore/Reservoir Dynamic Simulation
Authors: Hu Bin , Sagen Jan , Chupin Gaël , Haugset Tor , Ek Arild , Sommersel Tor , Xu Zheng Gang , Mantecon Juan Carlos 
Published: December 2007

Abstract
A comprehensive dynamic wellbore/reservoir flow model is successfully built by implicitly coupling a wellbore flow model with a near-wellbore reservoir model. The integrated model can be used to simulate various well flow transients that are subject to wellbore/reservoir dynamic interactions.
In order to evaluate its performance, several hypothetic cases, such as well shut-in/start-up, heading, coning, and crossflow, are simulated. Comparison is made between the integrated approach and the conventional IPR approach, and the advantage of using the integrated model is justified.
With given completion details and early-time reservoir data, the integrated model is then used to simulate a pressure buildup and drawdown test of an appraisal gas well. The simulation results show that the model can easily and accurately match the well testing data only by tuning the skin factor, which indicates the integrated model is suitable for optimizing well testing design, assisting well testing interpretation, and estimating the BHP where downhole measurements are not cost-effective and reliable.
Advanced Geological Modeling and Uncertainty Analysis in a Complex Clastic Gas Reservoir From Saudi Arabia
Authors: Al Maskeen Abdul Mohsen A. 
Published: December 2007

Abstract
This study deals with quantitative detection of factors affecting volumetric uncertainty in Jauf reservoir in Saudi Arabia. The Devonian clastic Jauf reservoir is complex, pinched-out, highly faulted, and stratigraphic trap, limited by an erosional truncation due to a regional Pre Unayzah Unconformity (PUU). The Jauf Formation was developed in a tidally-influenced sequence of shallow marine to fluvial sandstones.
Latest technology for geological modeling allowed the construction of a sophisticated model, integrating various types of data. This complex geological model incorporates a set of faults and an erosional unconformity surface, explicitly determined from seismic, and facies interpreted from core and log evaluation. A special study was conducted to explain the factors of volumetric uncertainty. Structural uncertainties, affecting both the unconformity and faulted blocks, were studied to explain the volume of the reservoir. Additional sensitivity analysis was performed for facies, porosity and gas water contact to evaluate the normalized volumetric uncertainty. Uncertainty analysis was made to identify the number of uncertain attributes. The simulation models were built through the derivative tree of ten different scenarios with hundreds of realizations using critical geological factors such as facies, porosity, structural and fluid contacts. The study showed that, using currently available data, the major factors affecting the uncertainty are the erosional unconformity surface (PUU), and the facies distribution.
Applications of Temperature Transient Analysis for Welltest Interpretation and Well Productivity Evaluation
Authors: Bahrami Nick , Siavoshi Jamal 
Published: December 2007

Abstract
During transient tests, both pressure and temperature change depending on downhole flow rate. In gas producing wells, Joule-Thomson cooling and frictional heating effects are the main dynamic factors that cause flowing bottomhole temperature to differ from the static formation temperature at that depth. When a gas well is shut in, JT cooling effect is vanished and this causes a sudden sharp increase in sandface temperature. Then as the effect of wellbore storage ends, wellbore temperature gradually cools down due to heat conduction with near wellbore region.
This paper demonstrates the applications of temperature transient data and proposes a new technique for using temperature transient data in gas wells in order to determine end of wellbore storage. Also, the effects of permeability and well productivity on temperature behavior are discussed. Three field examples are shown in which both temperature and pressure transient data were analyzed for more accurate welltest interpretation. This paper shows how knowledge of Joule-Thomson cooling effect and frictional heating effect can be applied for reservoir characterization.
Technology Used To Improve Drilling Performance and Primary Cementing Success in Katy Field
Authors: Cowthran James L. 
Published: December 2007

ABSTRACT
This paper presents several improved drilling and cementing techniques utilized by Exxon Company, U.S.A. in the Katy gas field at Katy, Texas. The data presented depicts the results of past versus present field practices in cementing and bit selection. Also included is a description of some problems that, affect drilling operations and cementing in the field. These problems include severe lost circulation, pipe sticking, and cementing failures caused by drawndown Cock-field sands.
Determination of Cuttings Lag in Horizontal and Deviated Wells
Authors: Garcia-Hernandez Augusto , Miska Stefan Z. , Yu Mengjiao , Takach Nicholas E. , Zettner Claudia 
Published: December 2007

AbstractThe objective of this study is to experimentally determine the cuttings lag or slip velocity in horizontal and high-angle borehole configurations. Cuttings lag is a critical component of an accurate determination of the cuttings' source depth, which is important for determining properties (type, strength, porosity, etc.) of drilled formations.Unique experiments were conducted at simulated downhole conditions using a flow loop with a transparent, 100-ft x 8-in x 4.5-in annulus. In these experiments, the time range for specially marked cuttings to travel through the annulus was measured optically. In addition, cuttings bed height, volumetric cuttings concentration and pressure drop across the test section were measured. The effects of flow rate, pipe rotation, and loop inclination angle on cuttings lag were investigated using two test fluids: water and an aqueous polymer-based (PAC) drilling fluid.In these experiments, the average cuttings lag was nearly 40% of the fluid velocity (i.e., the cuttings traveled at 60% of the fluid velocity). Pipe rotation increased the cuttings velocity even after accounting for the effect of cuttings bed height on the fluid velocity. A change in inclination from 90 deg (horizontal) to 70 deg reduced the slip velocity by 17%. Three distinct cuttings behaviors were observed: a stationary cuttings bed, a moving layer at the top of the cuttings bed and suspended cuttings. The primary mode for cuttings transport occurred in the moving cuttings layer. The size of this layer was affected by the test fluid.A cuttings lag model was developed from the experimental data. The model calculates the cuttings source depth given operational parameters (rheology, mud weight, flow rate, hole size, drill pipe size and ROP) for a doublebuild and hold wellpath. This model is a useful tool for drilling optimization and well planning. A better characterization of the formation while drilling helps to make better decisions to optimize drill bit and drilling fluid selection. The model also aids in rate of penetration determination. This improves the drilling process, leading to less drilling time and cost savings.
A Laboratory and Field Evaluation of a Technique for Hydraulic Fracturing Stimulation of Deep Wells
Authors: Conway Michael W. , Harris Lawrence E. 
Published: December 2007

ABSTRACTS
In 1981, over 1,000 new wells were drilled below 15,000 feet1. Although bottom hole temperatures in these wells vary widely, all have a number of similar characteristics which make hydraulic fracturing treatments very difficult.
These similarities may include high bottom hole pressures and temperatures, small diameter tubing, high closure pressures, low permeabilities, and tubing contraction problems while treating. The high treating pressures encountered necessitate the use of fluids with minimal pumping friction pressures. The high closure pressures often require the use of high strength proppants which are more difficult to transport than sand. Low formation permeabilities dictate the need for long propped fractures to achieve the desired production increase and thus long term fluid stability is required. To minimize contraction in long tubing strings, treating fluids often must be preheated (100–140°F). The high initial fluid temperatures can alter fluid properties downhole.
The expected effective viscosity of treating fluids as a function of time and temperature are of key importance to the design of stimulation treatments for these wells. In most cases, crosslinked gels are the fluid of choice for stimulation treatments, and most crosslinked fluidsare shear history dependent, therefore possessing no unique rheological characteristics. The variable conditions encountered during the treatment such as tubing size, pump rate, surface fluid temperature and pipe time influence the rheological properties observed.
A laboratory method has been developed to more concisely evaluate the role of the above parameters and data will be presented demonstrating the magnitude of the effects on the time-temperature stability of the crosslinked fluid. Results from both a laboratory and field evaluation of various techniques will be discussed. By achieving conditions where most of the crosslinked fluid viscosity is obtained in the fracture, a much higher viscosity and pipe shear independent fluid is obtained. The rheological data generated on the fluid is also more reliable.
Development and Use of a Simulation Model for Mobility/Conformance Control Using a pH-Sensitive Polymer
Authors: Benson I. , Nghiem L. X. , Bryant S. L. , Sharma M. M. , Huh C. 
Published: December 2007

AbstractInjection of a pH-sensitive polymer has been proposed recently as a novel deep-penetrating mobility control method, and the development of a simulation capability for its scale-up is reported here. An aqueous dispersion of polymer microgel, whose swelling property shows a strong dependence on pH, preferentially flows into high-permeability zones under acidic conditions. Since the injected fluid viscosity is low, small injection pressures are needed to inject the polymer. Geochemical reactions increase the pH, causing the polymer-containing fluid to experience a viscosity increase of several orders of magnitude thereby altering the flow pattern of subsequently injected fluid. Because the viscosity of microgel dispersions can be controlled with adjustment of pH, this process can be employed both as a deep-penetrating mobility control method (with moderate polymer viscosity) and as a conformance control method (with immobile gel generation).Polymer-bank placement design and process scale-up requires simulation of transport of microgel, acid-mineral geochemical reactions, pH changes, and the coupling between aqueous phase composition and viscosity. Such a capability has been implemented in a commercial reservoir simulator and preliminary simulations verify the operation and effectiveness of the complex new features, which can describe both the mobility and conformance control applications. Determination of reservoir mineralogy and mineral reaction rates is critical to modeling in-situ pH changes accurately. History matching of coreflood acid injection experiments was used to estimate geochemical reactions and reaction rates occurring in Berea cores. Linear and radial geometry floods in 2-layer reservoir models were carried out as preliminary scale-up simulations. Acidic fluids can be propagated farther into a reservoir in a low-pH state, using high injection velocity, an acid preflush, or weak acids. The Damkohler number was found to be a useful dimensionless quantity for characterizing acid floods with pH-sensitive polymer. Slugs of pH-sensitive polymer improve oil recovery better than continuous polymer flooding or waterflooding.The simulator was successfully used to history match coreflood experiments, to model techniques to propagate low-pH fluids deep into reservoir, and to demonstrate the effectiveness of pH-sensitive polymer slug treatments for conformance control.
A Study of Gel Degradation, Surface Tension, and Their Impact on the Productivity of Hydraulically Fractured Gas Wells
Authors: Nasr-El-Din H. A. , Al-Mohammed A. M. , Al-Aamri A. D. , Al-Fuwaires O. A. 
Published: December 2007

AbstractHigh pH borate gels have been used in fracturing deep gas reservoirs in Saudi Arabia. Guar and hydroxypropyl guar are used at various concentrations up to 45 lb/1000 gals. A breaker (regular or encapsulated oxidizers, guar-specific enzyme, or combinations of these breakers) is usually used to degrade the gel after the fracturing treatment. Field results indicated that the cleaning time following fracturing treatments was too long. Unbroken gel was noted in the flow back samples of some wells. This study was conducted to assess the effectiveness of various breakers that are used in the field, and determine other parameters that may affect the time needed to clean-up fractured wells.This paper presents the results of a detailed study done to evaluate the performance of several breakers at typical field conditions. The apparent viscosity of various borate gels was measured as a function of breaker type and concentration. Gel degradation was followed in a high temperature/high pressure see-through cell. The surface tension of various gel filtrates was measured as a function of temperature up to 150°C.Viscosity measurements indicated that all oxidizers degraded high pH borate gels, however the time needed to degrade the gel was found to be a function of breaker type and concentration; temperature and polymer loading. All guar-based gels produced a residue after reacting with the breaker. This residue was noted irrespective of the type and concentration of the breaker used. The residue was noted with gels formed using either guar gum or hydroxylproply guar. This residue may adversely affect the conductivity of the fracture.Surface tension measurements indicated for the first time that the surface tension of borate gels is high, which will enhance water blockage and hence reduce gas production. This paper examines factors affecting gel degradation, surface tension of borate gel filtrate, and their impact on well productivity.