bluuebunny/crossref_metadata_2025_split huggingface dataset:
New Class of Meter Solves Old Problem Impacting Well Test Accuracy
Authors: Ward E. R. 
Published: December 2007

Abstract
For the first time in a BP-operated asset, the impact of entrained free gas (not solution gas) in the liquid outlet line of a well test separator is quantified for the purpose of correcting gross fluid volumes and density measurement. This paper describes the results of deploying a sonar based, clamp-on gas void fraction (GVF) meter at a test facility in the Prudhoe Bay Unit (PBU) on Alaska's North Slope.
This particular test facility employs a coriolis meter to measure density and gross flow rate of the oil/water mixture. It was confirmed that discrepancies in allocation factors and individual net oil measurements, especially for cold high viscous crude oil, was due in part to unrecognized gas carry-under in the liquid outlet. Measured GVF associated with wells flowing ‘non-viscous’ oil, the less viscous crude (22 to 32 API) ranged from 0 – 2.0 %, whereas the GVF of wells flowing viscous crude (17 to 22 API) was between 0 – 8% at normal vessel liquid levels increasing to &gt;20% at reduced separator levels.
The additional secondary phase measurement enables PBU to now report real time corrected densities and volumes using an in-house method to calculate water cut. In addition to viscous crude, we believe that application of this technology to smaller, somewhat under-sized separators with less stable operations will provide value across the industry.
Well testing importance is increasing on the maturing fields of the North Slope of Alaska as it is not only used for the critical function of field management that ensures optimum production from a field; it also is a regulatory requirement set by the State of Alaska and may be used for Production Volume Accounting on fields with co-mingled production facilities.
Using High Resolution Lithofacies from Spectroscopy Logs and Microresistivity Images to Optimize Formation Pressure, Sampling, and Interference Testing Operations
Authors: Kear George R. , Kumar Anish , Donaghy Eileen , Guillory Christina , Elshahawi Hani , Ardila Mario , Williamson David , Cantwell Wesley , Briscoe Brian 
Published: December 2007

Abstract
Downhole pressure sampling and vertical interference tests are being conducted more and more as standard practice in the Gulf of Mexico and other deep-water provinces. A key input into the planning of these operations is an accurate understanding of the subsurface lithology, including subtle reservoir internal baffles and barriers. Not only is it necessary to understand where, in depth, the zones of interest exist, but also their compositions.
Log-derived high-resolution mineral-based lithofacies can be used to improve the planning of downhole sampling operations and post-operational analysis. These are computed using borehole spectroscopy and high-resolution micro-resistivity image data. The spectroscopy data is used to classify the rocks into dry-weight mineralogy-based lithofacies based on a specifically designed ternary-diagram classification system. Calibrated high-resolution micro-resistivity image data is integrated with the generated dry-weight mineralogy-based lithofacies to compute a final mineral-based high-resolution set of lithofacies. All the computations can be accomplished on a workstation within a short time. The final lithofacies can be presented as a detailed geological column, or be input, as numerical data, for additional computation and modeling.
These lithofacies can be used to make sampling and pressure point selections. The speed of computation makes them useable for this purpose. The output can be quickly delivered to the decision makers whether in the office or at a remote location. The geological display of the lithofacies makes it readily usable and preferred for choosing sampling locations, whether for pressure or fluids. The inherent mineralogical content combined with the higher resolution bedding directly addresses the need to identify potential zones of interest otherwise indistinguishable. Critical depositional events such as maximum flooding surfaces, condensed sections, reservoir seals such as marl layers and shales, continuous or interbedded, are immediately identifiable with these lithofacies.
The use of log-derived high-resolution mineral-based lithofacies helps place the tool probes and/or packers at optimum formation and depth locations, thereby reducing risk and operating time, easing interpretation, and maximizing data and sample recovery.
Strategies and Techniques for a Giant Sandstone Oilfield Development: A Road Map to Maximize Recovery
Authors: Lu XiaoGuang , Wang YuPu , Zhang YongQing 
Published: December 2007

Abstract
Daqing, the largest heterogeneous multi-layer none marine reservoir oilfield in China celebrated its 45th birthday in Ocotober 2005. Boasting 27 continuous years of plateau oil production over one MMBOD, the largest industry polymer-flooding oilfield in the world, and excellent developing effect, its development strategies and techniques applied provide a road map to maximize oil recovery: Life cycle reservoir studies give insight into reservoir, and provide a foundation for plan of development, implementation of infilling, and associated workover jobs such as zonal stimulation, zonal water plugging.Early reservoir pressure maintenance by internal water flooding maintains reservoir pressure close to its original status, providing sufficient reservoir energy, enabling high and stable production rate for a long period as well as improving recovery.Performance monitoring conducted in the whole process of development, of which, separate layer performance monitoring is one of the most important foundation for in-depth understanding subsurface development potential.Pilot tests are conducted before any key development strategies and measures are applied to ensure their success.Separate layer production/water injection of multi-layer and heterogeneous reservoir and novel completion are the key measures for enhancing poorly drained reservoir water flooding, improving its sweeping efficiency.Multi-time and progressive infilling drilling develops bypass oil resulting from the geological complexities of reservoirs.Widely applying polymer flooding enhances oil recovery by over 10%.Innovative technology makes development of marginal reservoirs/fields economical.
Outstanding development of the giant field has proven the validity of above strategies and techniques with an oil recovery factor current at over 51% in the main block.
Laboratory Aspect of Chemical EOR Processes Evaluation for Malaysian Oilfields
Authors: Ibrahim Zahari , Manap Arif Azhan Abdul , Hamid Pauziyah Abdul , Yee Vai Hon , Hong Lim Peng , Wyatt Kon 
Published: December 2007

ABSTRACT
Chemical Enhanced Oil Recovery (EOR) processes are being considered for large field applications with recent high price of crude oil. However, applications are generally directed towards onshore environment, with temperature less than 85°C, using fresh water as the injection water. Malaysian oil fields are located offshore, with high reservoir temperatures of more than 100°C and use sea water as injection water. This paper reports on laboratory results that were part of an R&D project investigating the feasibility of increasing oil recovery through chemical EOR processes for oil fields in Malaysia.
Chemical EOR processes investigated include surfactant, surfactant-polymer, alkaline-surfactant, and alkaline-surfactant-polymer. A unique 2-stage softening prepared seawater for the two processes using alkali. Thermal aging studies at 119°C were used to screen chemicals for stability and degradation. Interfacial tension and phase behavior tests of stable chemicals were used to select formulations. Linear corefloods and thermal degradation tests were used to select polymers. Oil recovery studies used field proportioned injected chemical volumes in radial corefloods.
Dilute surfactant processes without alkali recovered little incremental oil. This was attributed to heavy consumption loss of surfactant. Average incremental oil recovery in coreflood studies by alkali-surfactant flooding was 14.6% OOIP and by alkaline-surfactant-polymer flooding was 28.6% OOIP respectively. This proved that there is potential for chemical EOR application in Malaysia.
The Use of Fractional Flow Theory for Foam Displacement in Presence of Oil
Authors: Mayberry D. J. , Kam S. I. 
Published: December 2007

Abstract
Foam has been extensively used in improved and enhanced oil recovery processes in the petroleum industry over decades. Foam is capable of reducing gas mobility dramatically in porous media, and thus helps displacement fronts stable by controlling the mobility ratio between injected gas and reservoir fluids. In this study, models were constructed to investigate the mechanisms of foam displacement in porous media using three-phase fractional flow theory and ternary diagrams. The strength of foam in the presence of oil was accounted for by using a mobility reduction factor (MRF) for the gas phase that can be routinely measured in laboratory coreflood experiments. The use of MRF is a typical way of describing foam rheology in local steady-state modeling.
Results were analysed in terms of saturation paths in the ternary diagrams, saturation velocities, sweep efficiency and effluent history. Two different initial conditions were selected to demonstrate the importance of initial saturation on the displacement: one with oil phase dominant ((Sw, So) = (0.2, 0.8)) and the other with water phase dominant ((Sw, So) = (0.8, 0.2)). At low MRF (i.e., no foam or weak foam), the efficiency of foam displacement was primarily governed by fast-moving spreading waves that rapidly broke through the porous medium resulting in poor sweep efficiency. An increase in MRF (i.e., stronger foam) altered the nature of the displacement front by making it more piston-like through the development of "shock" fronts and improved sweep efficiency significantly. Once shock fronts dominated the displacement, the importance of initial saturation on the mechanisms of displacement became less pronounced. Calculations also demonstrated that a decrease in oil viscosity made the oil phase more mobile and the formation of shock fronts more prolific, significantly enhancing sweep efficiency.
The results in this study imply that if basic fluid properties, injection and initial saturation conditions and MRF are known, one can reliably predict the mechanisms of foam displacement in porous media even in the presence of oil.
Revitalization of the Austrian Oilfields
Authors: Gugu Siegfried 
Published: December 2007

Abstract
Since the early 1940's OMV has produced oil and gas from the Austrian oilfields situated ~30 km northeast of Vienna. Currently around 850 oil wells produce ~5.5 MMbbl/a.
In order to ensure economic field life in decades to come, a number of projects are currently in realization or in planning phase.
One focus aims at drilling exploration wells adjacent to existing infrastructure in order to add additional reserves. The well locations are established by using extensive 3D seismic surveys, shot in and around of already producing fields. Beside the exploration wells drilling of infield producers ensure that the natural decline of the mature horizons can be minimized. Additionally production optimization (change of artificial lift systems, oil well automation, etc.) plays a crucial part in stabilizing production.
Another important factor of mature areas is the existing infrastructure. In OMV's case most of the infrastructure is already more than 30 to 50 years in place and has reached the end of its design life. Increasing maintenance costs and break downs make a renewal unavoidable. 3 major projects are currently in realization: Matzen NEW, Tank Farm NEW and Water Treatment NEW.
These projects will assure that the goal of a significant reduction of maintenance costs and of manpower will be achieved. This will go hand in hand with an increase in reliability and maintainability.
By 2010 all new projects will be completed and most of the old oil infrastructure will be renewed, streamlined and fully automated. Together with the forecasted production increase the Austrian oilfields will then be "Fit for the Future".
Identifying the Improved Oil Recovery Potential for a Depleted Reservoir in the Betty Field, Offshore Malaysia
Authors: Friedel T. , Sanza G. J. , Ali M. I. , Embong A. , Kasap E. , Yusoff S. , Cuauro A. 
Published: December 2007

Abstract
A reservoir simulation model, calibrated with 25 years of production history, was used to determine a cost effective reservoir management and production strategy, which optimises future recovery from an oil rim reservoir in the Betty Field, offshore Malaysia. The reservoirs consist of good quality sands in a coastal depositional environment with an anticlinal structure terminated at the crest with a growth fault. The history match confirmed that A6.0 reservoir, unlike all others in the field, which co-exist within a stacked sequence, is surprisingly isolated from the surrounding aquifers. Prior to its premature shut-in, oil production reached 5000 bopd. However, a drastic decline in reservoir pressure caused the evolution of a large secondary gas cap and a steeply increasing producing gas-oil ratio. The recovery factor for this reservoir stands at 25%, significantly less than for the best reservoirs in the field.
After more than a decade shut-in, secondary and tertiary recovery methods investigated in this study included dump flooding from adjacent reservoirs, gas re-injection and water injection based on an extensive prior screening exercise. The limited prospective increase in reserves highlighted the need for a technically sound but also financially feasible solution. Since the current facilities were not intended for any pressure maintenance or enhanced oil recovery scheme, a number of technical limits arose due to space and weight constraints on the platform. Furthermore, fluid separation and export constraints had to be taken into account. Consequently the reservoir management plan required a field-wide optimization of the scheduled activities in order to identify bottlenecks in the gas handling capacity. Simultaneously with the model study, shut-in wells' production potentials were re-tested in order to gather additional data and, a water dumpflood pilot was implemented.
Techniques of Reinjecting 100% of Produced Water in Daqing Oil Field
Authors: He Liu , Shushan Tang , Xiaoshu Li , Li Zeng 
Published: December 2007

Abstract
In the history of over 40 years of development, Daqing Oilfield has witnessed three phases of development: basic well pattern, infill well pattern, and tertiary oil recovery. To cope with that, three sets of systems including general produced water re-injection, produced water fine treatment re-injection, and polymer flooding produced water re-injection have been set up catering to the varied requirements in injection water quality of different well patterns. Among them, general water re-injection system feeds the basic well pattern and primary infill well pattern; fine treatment water re-injection system serves secondary and tertiary infill well pattern as well as marginal low-permeability oilfields; and polymer water reinjection system is dedicated mainly to polymer flooding blocks.
Aiming to satisfy the requirements of the oily produced water treatment and oilfield water re-injection development, and based on the specifications of the original produced liquid and output water, Daqing Oilfield water treatment system is divided into four subsystems, they are: general produced water treatment, produced water fine treatment, polymer flooding produced water treatment, and clear fresh water treatment.
Original liquid to the produced water treatment subsystem comes from water flooding and dehydration stations, part of the treated water is re-injected to the basic well pattern and the primary infill well pattern, the remaining portion goes through fine treatment before being re-injected into the secondary and the tertiary infill well patterns. Original produced liquid to the polymer flooding produced water treatment subsystem originates from polymer flooding and dehydration stations, and all of which is re-injected to the basic well pattern and the primary infill well patterns after being treated. As for the marginal low permeability oilfields, due to their low permeability, the original liquid coming from dehydration stations is treated straight in the fine treatment station before being totally re-injected, in locations where the produced water quantity can not satisfy the injection demand, underground water and surface water will be treated to reach quality required by the low permeability reservoir injection process.
The key process of the water re-injection technology is to treat the produced liquid into standards required by reinjection. This thesis is to introduce the produced water treatment technologies used in Daqing.
Expandable Casing In India
Authors: Roy Choudhuri Biplab 
Published: December 2007

Abstract
In drilling long drift side tracking well window was cut in 95/8 casing. After window cutting 81/2"hole drilled with kcl phpa (inhibitive) mud wt 12 ppg upto top of LIII. Reason for 12 ppg mud use due to shale instability above top of LIII. FROM LIII top to land point formation is lime stone and low pore pressure require gel polymer mud (low mud wt 8.6-8.7 ppg) drilling this two section leads to complication and well problem as 12 ppg mud will induce loss in limestone formation.
As from 95/8" casing window was cut and 7" liner was lowered to top of LIII next liner to lower 5" and thereafter 31/2 drain hole. 6" drain holedrilling was not possible. By adopting expandable liner system problem was solved. One extra set of 51/2 expadable liner was lowered. 51/2 " bicentre bit was lowered and 6" drain hole was done. Drilling procedure as belowLowered 7" linerLowered 61/8 " bit/6"×7" bicentre bit and enlarged to landing point using near bit 7" reamer. Lowered 51/2" expandable casing. Lowered 51/2" bi centre bit for making 6" drain hole.6" drain hole was possible to drill using expandable liner and drilling shale and low pressure loss zone isolating above two zone
An Integrated Approach to Reservoir Performance Monitoring and Analysis
Authors: Sugai K. , Nishikiori N. 
Published: December 2007

Abstract
This paper presents how an engineered process of monitoring and data analysis can improve reservoir management. Engineers can gain a clear picture of reservoirs by adapting the described approach. This paper demonstrates how our integrated approach can improve reservoir management from a viewpoint of production data analysis. A wide variety of oilfield data have been utilized for experiment and verification of our approach. Five case studies highlight key elements in the integrated approach. Each of the application and highlights of the results includes:
Improved oil rate estimation by integration of well test data and well modeling using Neural Networks. This method improves reliability of oil rate estimate by reducing vulnerability of Neural Networks. Well performance diagnostics by an innovative two dimensional plot of a specialized parameter. It has proved that simultaneous tracking of oil-and-water production is useful in performance-based well ranking. Water flood monitoring and diagnostic by Hall plot for injection wells and derivative of water-oil-ratio plot for production wells. This technique provides detailed information for subsurface water monitoring and control. Infill well drilling candidate selection by visualizing well drainage area superimposed onto geographical information. This quick-assistance approach has been proved consistent with the highly-detailed reservoir simulation. Acidizing optimization from data mining the best-practices by Neural Networks. This method has been proved applicable as an operational quality management tool.
The outlined approach and case studies have shown how the integrated process improves reservoir management in the life of field. The specific engineering methods described are all handy and they can be applicable for any type of oilfield.
Successes Achieved in Acidizing of Geothermal Wells in Indonesia
Authors: Mahajan M. , Pasikki R. , Gilmore T. , Riedel K. , Steinback S. 
Published: December 2007

Abstract
Geothermal reservoirs differ significantly from their hydrocarbon counterparts and so do their remedial treatments. Typically these reservoirs are naturally fractured volcanic sandstones with varying mineralogy found over a wide temperature range. Often the zones of low permeability limit the efficient recovery of heat from these reservoirs. The low permeability could either be inherent or induced by damages occurred while drilling and/or production phases. The drilling phase often experience significant fluid losses, which cool the well and near wellbore zone from the high bottom hole static temperature to the moderate levels that make drilling, cementing and completion of these wells possible. The loss of cuttings and drilling mud to permeable formations and/ or fractures is a major source of damage. Other potential damages occur when the well is put on production. As such it is common for these wells to experience a decline in production owing to such formation impairments.
Permeability in these zones may be enhanced through methods of well stimulation such as acidizing and high-rate injection. Such practices usually employing mixtures of hydrochloric and hydrofluoric acids in various concentrations, have widely been used worldwide but performance has been somewhat spotty and unpredictable. Also owing to the typical difficult locations of geothermal sites, there have been concerns about the logistical and QHSE aspects while planning conventional treatments.
A successful application of a unique acidizing system & other techniques into geothermal wells in Indonesia is presented in this paper. This acid system involves controlled in-situ generation of HF acids based on organo phosphonic acid chemistry. It provides unique advantages in geothermal application in terms of both the enhanced well performance and rightly addressing all the logistics/QHSE issues discussed above. The last treatment with this system resulted in almost 3 folds increase in productivity of well.