bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Role of Enhanced Production Logging Measurements in Challenging Openhole Horizontal Completions
Authors: Mukerji P. , Zaouali Z. , Rees H. 
Published: December 2007

Abstract
The keys to proactive production and reservoir management are production logs that profile fluid entries and diagnose problems in producing wells. Designing optimal production strategies and remedial operations requires high-confidence diagnosis. Production logging in high angle and horizontal wells producing mixtures of various phases is challenging because of complex flow regimes.
In this paper we present a field example that uses a new compact, integrated production-logging tool that incorporates the latest technological advances and best practices to address complex production-logging requirements. We are able to demonstrate the added value in terms of comprehensive flow diagnosis.
A production logging operation using the new tool, which specializes in horizontal and deviated well logging, was planned to obtain key inputs for the reservoir model and investigate reasons for low well productivity. Production logs from the new tool resulted in accurate flow diagnosis and led to better understanding of complex flow mechanisms across the horizontal section. These enhanced measurements were integrated with borehole imaging information leading to a better understanding of flow contribution from the matrix and fractures.
The tool provides a recording of holdup and velocity profiles along the vertical diameter of the borehole cross-section. Three sensor arrays, consisting of six optical probes, six electrical probes, and five spinners, are spread across the wellbore on retractable arms that can be opened and closed with a hydraulic sub to better locate holdup interfaces. The optical probes use the fluid's reflectance to derive the gas holdup, and the electrical probes measure the fluid's impedance to derive the water holdup. The spatial location of the different sensors is accurately known through the use of an integrated relative bearing sensor and a caliper measurement. The direct measurement of the velocity and fluid holdup enhances the capability of the analyst to determine an accurate downhole flow profile.
An Organized Approach: Challenges Faced by Today's New Engineers in the Petroleum Industry
Authors: Edwards J. T. , Woo G. T. 
Published: December 2007

Abstract
Today the knowledge gap between the "seasoned professional" and "new hire" to the petroleum industry has reached a new level of disparity. Due to market trends and job availabilities in prior years, many engineers have been turned away from futures in oil and gas. But with the current global demand for energy at an all time high, companies are now looking for fresh faces to fill their empty seats.
It is not out of the norm for a new engineer to step into a role and see a dramatic split among his peer group of engineers. Many of those in the industry today have on average 10 to 15 years experience working in the oil and gas industry, which reflects the time of the last major market upswing. The challenge arises in bridging generational as well as technological gaps to allow for quality job performance and precise communication among varied experience levels of engineers.
In navigating the new profession, the right questions need to be asked by the young engineer. Nothing can be assumed or taken for granted. No matter what role the engineer holds in the disciplines of drilling, completions, reservoirs, or operations, a level of responsibility will be assigned but we must ensure it comes with clear definitions and expectations.
There is not always a choice of tasks or even the luxury of transition periods in today's oil and gas industry. More positions are becoming available each day with a smaller pool of applicants who poses the desired years of experience. This forces companies to fill openings with many candidates fresh from college and in some instances, with minimal hands-on experience. This paper will be a guide for today's new engineer with suggestions for how to succeed in this essential global industry.
Water Shutoff Treatments Using an Internally Catalyzed System in Boscan Field: Case Histories
Authors: Mata F. , Ali S. , Cordova Ernesto 
Published: December 2007

Abstract
This paper describes the results obtained using an Internally-Catalyzed System1 (ICS) to reduce water production in the Boscan oil field, near Maracaibo, West Venezuela.
This field is divided in two blocks: north and south. In the south block, wells can eventually produce oil with 90% water cut, due to the influence of an aquifer. The accumulated production per well can be as high as 6 (six) million barrels, and typical rates range from 600 to 2,400 BFPD (barrels of fluid per day).
In order to mitigate the high water cut and water production, the operator implemented in 1998 a water shut-off (WSO) program. In 2003, the ICS was introduced as part of this program. The ICS is solids-free and internally activated. It is used for permanent zone plugging, and lost circulation control, delivered into the matrix of the targeted zone. Laboratory evaluations were conducted to determine effects on the hard setting of ICS, resulting from the contact between ICS and other fluids deployed on well construction, and well production enhancement, as well as reservoir fluids, acids, cement filtrate, brines, formation water and crude oil.
This paper summarizes the results of 19 WSO jobs performed. . In some specific wells, water cut decreased by 20%; on others, by 70%, with consequent oil production increase in some cases of more than 400 BOPD per well. The WSO treatments have been designed for deeper formation penetration, and long-lasting water blockage. Applied WSO treatments with ICS have been found to effectively block water production over a long period. Cost of treatments has been paid out within approximately 45 days.
This paper includes laboratory tests, operational procedures and results for each treatment done with ICS technology, demonstrating to be an excellent option to enhance oil recovery on mature fields with water high water production.
In-Field Emulsion Treatability Test With the Electrostatic Susceptibility Tester
Authors: Lee J. , Frankiewicz T. , Ismail M. Z. , Anwar M. L. , Samad M. S. A. 
Published: December 2007

Abstract
An Electrostatic Susceptability Tester (EST) was used to determine the treatability of oil emulsions from the Miri Crude Oil Terminal (MCOT). In the EST, a sample of heated, chemically treated emulsion is exposed to an AC/DC electrostatic field and the energy and time required to coalesce water droplets and separate water from the oil emulsion are determined. Both fresh emulsions from the trunk lines to the plant and aged emulsion from a holding tank at the terminal were tested. It was concluded that electrostatic treatment is effective for treating the fresh emulsions at 50 °C with the injection of either acetic acid or emulsion breaker. The dry oil BS&W was reduced from 2.5 vol% to 0.3 vol% when acetic acid injection rate was increased from 250 ppm to the range of 500-1000 ppm. The naturally occurring surfactant (calcium napthnate) that stabilized the emulsion tends to dissolve into the oil phase at higher acetic acid concentrations, thus making the emulsion easier to be treated. Electrostatic treatment is not as effective for treating the aged emulsion from the holding tank because the emulsion contained greater than 40% water and was apparently stabilized by a combination of calcium napthenate and fine, oil-wet solids.
A Multidisciplinary Approach to Hydraulic Fracturing in the South Texas Wilcox Formation
Authors: Britt L. K. , Smith M. B. , Haddad Z. , Lawrence P. 
Published: December 2007

Abstract
The objective of hydraulic fracturing is to design and execute a fracture stimulation that achieves the desired fracture dimensions (length & conductivity) to maximize well productivity and reserve recovery. In order to truly achieve this objective information from the geosciences and engineering disciplines are required.
Geologic, geophysical, and petrophysical data are needed to understand reservoir quality, thickness, and extent. Reservoir engineering data is used to assess in-place hydrocarbons, flow capacity, permeability, and reservoir drainage area. Production decline analysis is used to assess reserve recovery and corroborate in-place hydrocarbons and flow capacity. Rock mechanics is used to assess the elastic properties of the formation of interest, bounding sediments, as well as the fracture mechanics. Finally, completion and stimulation engineering are used to design, execute, and evaluate the hydraulic fracture treatment. All of these data and disciplines are needed to truly optimize the fracture stimulations, production rate, and reserve recovery.
In recent years, there has been much discussion regarding the causes for, or reasons that the dimensions of the hydraulic fracture are shorter and less conductive than desired. These causes include: relative permeability effects1, fracture fluid cleanup2-5 and gel damage6-12, multi-phase and non-Darcy flow13-15. In addition, reservoir heterogeneities, layering, and boundaries can result in less than optimal dimensions as well. These effects have been investigated; however, without the integration of quality multi-discipline data determining the inter-relationship or causal relationships of these effects is difficult. As a result, the factors truly affecting the fracture dimensions may be misinterpreted or misrepresented resulting in less than optimal results.
This paper will document a multi-discipline investigation of a multi-well South Texas Wilcox Field used to improve and optimize hydraulic fracture treatments in the area. The integration of this dataset will be used to determine fracture dimensions and assess the critical parameters for the creation of optimum fracture dimensions.
Bokor—A New Look at Sand Production in a Mature Field
Authors: Kasim A. , Wijnands F. , Subbiah S. 
Published: December 2007

Abstract
Although the stacked reservoirs of the Bokor field, offshore Sarawak, Malaysia are prone to sand production, the field development team did not a-priori opt for gravel packs in every well. While such completions can indeed eliminate sanding risk, the team also wanted to consider the impact of the completion on the production rate of a well. The optimum completion not only excludes sand, after all. It also maximizes hydrocarbon production.
We carried out a geomechanics and sand production study, using readily available data. The paper gives an insight in the physics of sand production and how this process can be geomechanically modeled. It shows how the model is used to select feasible completions and quantify sand-free production rates, over the life of the reservoir.
One important outcome was that screenless completions were possible in the deeper reservoirs by optimizing perforation orientations. Apart from other advantages of screenless completions, this leads to significant potential increases in sand free production rates.
An integrated Sand Management process brought together geomechanics, petrophysics, reservoir and completion engineering to truly optimize completions.
Effective Gas Shutoff Treatments in a Fractured Carbonate Field in Oman
Authors: Ali E. , Bergren F. E. , DeMestre P. , Biezen E. , van Eijden J. 
Published: December 2007

Abstract
A giant fractured carbonate field in north Oman has both complex geology and complex reservoir drive mechanisms. The upper densely fractured layers are produced using the gas oil gravity drainage (GOGD) process, while the less fractured lower set of layers is subjected to water flooding. The production from the GOGD layers is through vertical and horizontal wells completed in a thin fracture oil rim. Gas conformance control is a challenge in many of these wells as the gas breakthrough occurs for a variety of reasons: 1) downward movement of fracture gas-oil contact (fracture oil rim thinning), 2) gas breakthrough via high conductivity fractures (fracture gas breakthrough), 3) zonal isolation failure at the wellbore (mechanical gas breakthrough) and 4) increasing gas saturation in the matrix (matrix gas breakthrough). An integrated multidisciplinary team studied well and reservoir performance and open-hole and cased-hole logs to diagnose the source of higher than expected GOR in several GOGD wells. The most important logs in this work were MPLT surveys used to identify the sources of gas production and FMI logs used for fracture identification and characterization.
This paper illustrates the work carried out in horizontal openhole and vertical cased-hole completions in a giant fractured carbonate field to successfully shut-off the undesirable gas flow. The horizontal wells identified with poor zonal isolation behind the liner were treated with an innovative gel gas shut-off procedure. The merits of this procedure outweighed other solutions: targeted placement; a strong full-blocking gel to fill up channels behind the liner, inert particles to control fluid loss of the full blocking gel to small fractures and the formation matrix, and displacement with an already cured gel which could be washed out of the wellbore.
Significant drops in the GORs of these wells resulted in sustained oil production gains. This is a step change in the ability to manage detrimental gas production in this field and is expected to lead to further opportunities for improved gas management and well performance in this field and other fields where the GOGD recovery mechanism is used.
Mechanistic/Probabilistic Modeling of Slug Initiation in a Lower Elbow of a Hilly-Terrain Pipeline
Authors: Al-safran E. M. , Sarica C. , Zhang H. -Q. , Brill J. P. 
Published: December 2007

Abstract
Probabilistic/mechanistic modeling was carried out to develop a predictive model for initiated slug length distribution at the lower elbow of a hilly-terrain pipeline. Statistical analysis suggested the appropriateness of a Log-Normal model over an Inverse Gaussian model. The Log-Normal model is correlated by two empirical relationships developed for mean slug length and slug length standard deviation. Based on experimental observations, the approach of critical liquid level (instead of critical liquid volume) was adopted as the slug initiation criterion at the lower elbow. Consequently, the critical liquid level was mechanistically modeled and empirically correlated to the initiated mean slug length and standard deviation. A model validation study demonstrated the capability of the probabilistic/mechanistic models to reproduce experimental data with a satisfactory match. The match is improved when the developed correlations were tuned using the statistical confidence intervals of their coefficients.
Practical Steps to Increase Production and Reserves in Mature Gas Fields: Hugoton and Panoma, Texas County, Oklahoma, U.S.A.
Authors: Lisigurski O. , Rowe G. C. 
Published: December 2007

Abstract
When working in mature fields, one needs a lot of imagination because many times economic resources are limited. Workovers, that utilize proven and new technology may solve this problem. Using existing wells that already have casing, tubing, artificial lift systems and surface facilities is an excellent way to increase reserves and production with a small investment. Identifying the candidates for the workovers is the key to success.
In 2005, 43 wells were worked over in the Texas County, Oklahoma area of the Hugoton and Panoma Fields, resulting in a production increase of 2,914 MSCFD for a total cost of only $1.6 MM. Payout of the program occurred in just 4.6 months, using a conservative gas price of only $3.89 per MSCF. The techniques involved fracture stimulation, mechanical wellbore cleanouts, artificial lift type changes and acidizing. A successful workover program should apply the fundamentals of science and engineering, coupled with field operations and geology. The screening methods developed may lead to further workover activity with anticipated reserve and production increases in other areas of the Hugoton and Panoma Fields.
Improved Optimisation of Bit Selection Using Mathematically Modelled Bit-Performance Indices
Authors: Clegg John , Barton Steve 
Published: December 2007

Abstract
Despite the development of models describing Polycrystalline Diamond Compact (PDC) bit performance, bit selection is often made on the basis of visible, geometric features.
Bits can now be modelled routinely and described in terms of their technical interaction with the drilling assembly and the formation. Selection on the basis of modelling and this interaction is novel and valuable, and will make for more consistent selection and improved performance.
A new set of performance indices is presented for PDC bits. These are derived from a sophisticated mathematical model and describe performance in terms of:ROP – Rate of Penetration, or how fast the bit will drill for a given Weight on Bit (WOB)Durability – how resistant the bit is to abrasive wearStability – how resistant the bit is to lateral vibrationSteerability – how the bit responds to side forces and therefore how steerable it is on Rotary Steerable Systems.
Once the relative importance of each index is established, the optimal bit for the specific application can be selected.
A specialist interface is presented for Rotary Steerable Systems. Using this, the user can input system type (from the variety of systems available) and well profile, and the software will create a list of bits ranked by decreasing suitability, based on a variety of factors including some aspects of bit geometry but primarily mathematically modelled response.
The paper presents results from pilot studies and demonstrates a scientific and rational approach to bit selection – giving not only improved but also more consistent and reliable results.
An Integrated Approach to Parameterize Reservoir Models for CO2 Injection in Aquifers
Authors: Egermann P. , Chalbaud C. , Duquerroix J. -P. , Gallo Y. Le 
Published: December 2007

Abstract
The injection of carbon dioxide in oil and gas reservoirs (Enhanced Hydrocarbon Recovery, EHR) or in aquifers is a promising way to cope with the short-medium term issue of greenhouse gas emission mitigation. Although CO2-EHR projects represent the best economical opportunities, the CO2 injection projects in deep aquifers offer the largest capacity potential for long-term CO2 storage. The design of a CO2 injection project mainly depends on the results of reservoir models.
To be predictive, the numerical tools have to be parameterized to adequately model the multiphase flow behavior (relative permeability curves) and the phase exchanges between the injected fluids and the fluids in place (thermodynamic equilibrium). In the particular case of the CO2 injection, the potential rock/fluid interactions with the host formation must also be studied carefully as a function of the thermodynamic conditions, the fluid compositions, the rock mineralogy but also the flow regime (i.e. the distance to the well bore).
This paper presents an integrated workflow based on experiments and numerical simulations to determine in a comprehensive and robust manner the appropriate parameters at the core scale for a CO2 injection in aquifer. CO2 injection experiments were conducted under reservoir conditions. Experiment were carried out on companion plugs under several thermodynamic conditions and with different fluid systems (different brine salinities) in order to collect data (production curves and differential pressure evolution as a function of time) over a wide range of CO2 storage conditions. Then, these experiments were modeled using a compositional simulator dedicated to CO2 geological storage.
Using this approach, we show that an unique set of parameters enables modeling of CO2 injection for various thermodynamic conditions and fluid systems. Therefore, such approach leads to predictive simulations at the core scale, which contributes to the accuracy of the performance prediction of the CO2 injection at the reservoir scale, if the main geological features (heterogeneities) are included into the large scale model.
Combined Microbial Surfactant-Polymer System for Improved Oil Mobility and Conformance Control
Authors: Gabitto J. F. 
Published: December 2007

ABSTRACT
Microbial enhanced oil recovery (MEOR) technologies have become established as cost-effective solutions for declining oil production. The demonstrated versatility of microorganisms can be used to design advanced microbial systems to treat multiple production problems in complex, heterogeneous reservoirs. This research project presents the concept of a combined microbial surfactant-polymer system for advanced oil recovery. The surfactant-polymer system utilizes bacteria that are capable of both biosurfactant production and metabolically-controlled biopolymer production.
This article describes the results of our laboratory work to grow microbial cultures and the work done on recovery experiments on core rocks. A bacterial strain capable of producing both surfactant and polymers has been selected. Laboratory experiments to determine under what conditions surfactants and polymers can be produced from one single strain have been conducted. Recovery experiments to determine the performance of these strains under different conditions have been carried out. Experimental results show a significant influence of nutrient regime on alternate production of surfactants or polymers for a Bacillus licheniformis strain, NIPER 1A.
Development of a Low-Frequency Quadrupole Shear-Wave Technology to Improve Quality of LWD Shear Velocity Measurement
Authors: Tang X. M. , Dubinsky V. , Patterson D. 
Published: December 2007

Abstract
We present the result of a new development in the logging while drilling (LWD) quadrupole shear-wave technology that was recently developed to measure formation shear velocity in the LWD environment. Due to the severity of drilling noise in the low-frequency (0-3 kHz) range, initial development focused on measurements around 4 kHz, although the quadrupole attains formation shear velocity in a lower frequency range (~2-3 kHz). The 4-kHz quadrupole data is prone to dispersion, especially when drilling with a heavy mud. The dispersion can cause uncertainties in the shear velocity measurement. Realizing the potential enhancement of the measurement, we further develop the technology to perform measurements in the 2-3 kHz range or lower. The key in this new development is enhancing the quadrupole wave energy significantly above the noise level in the designated low-frequency range. Data from this new measurement have been acquired and analyzed. Comparison has been made between the new measurement and the measurement made with the 4-kHz source. Despite the common belief that drilling noise prohibits LWD acoustic measurements toward low frequencies, we obtain quite coherent quadrupole data in the low-frequency range. More importantly, the low-frequency quadrupole shows minimal dispersion and indeed attains the formation shear velocity, in agreement with the LWD quadrupole wave theory. The new development constitutes a significant improvement in the LWD quadrupole shear-wave technology.