bluuebunny/crossref_metadata_2025_split huggingface dataset:
Oil Invasion in Gas Zone and Sweep Efficiency Due to Stratigraphic Barrier in an Active Waterdrive System, Hollin Formation, Ecuador
Authors: Ucan Sezai , Olmos Sebastian , Rios Sergio , Marin Horacio 
Published: December 2007

Abstract
The main objective of this study was to describe the nature, distribution, and physical characteristics of the reservoir, by integrating geophysical, geological, petrophysical, and production data in a three dimensional geological and simulation model that represents the behavior of the Hollin reservoir in Bermejo field. The Hollin reservoir required significantly higher effort due to the strong aquifer, the complex relationship between heterogeneity influences, the movement of the water from the aquifer into the reservoir, water and gas conning, stagnation of unproduced oil zones, and migration of oil towards gas zones.
When production data was analyzed, it was determined that even thin shales (on the order of 2-5 ft. or greater) played a role in enhancing reservoir production by delaying water and gas conning and water influx in the Hollin fluvial sandstone. Mapping the shale barriers was as important as mapping the sand bodies. It was decided to correlate the shales interpreted from well log data and introduce shale tops and bases in the geological model. Therefore, in the geological and simulation models shales have been modeled explicitly, down to a five foot resolution.
A Stratigraphic geocellular model was constructed to describe the 3D petrophysical properties, calculate hydrocarbons in place and to prepare reservoir simulation grids. Geological models incorporating shales were modeled. If shale was locally absent, the "shale zone" was assigned the appropriate reservoir properties determined from well and/or seismically derived attributes. J-Function analysis was implemented successfully in assigning oil saturation. Calculated oil saturation profiles at initial and current times were compared with initial well log oil saturations.
History matching and initialization were conducted to validate geological, petrophysical, PVT, and reservoir models. Flooded and non-flooded regions of reservoir, current WOC and GOC were identified. Areal extent of localized thin shale lenses were modified during history, matching active water breakthrough well by well. The amount of oil invasion in the original gas zone, stagnated oil, and gas contraction volumes were calculated in the most productive marker, Naranja. Current GOC has moved from the original GOC position. Actually, the amount of oil invasion was not significant when it was compared to the volume of stagnated oil.
When geological and simulation models are built and data gathered according reservoir specific problems, successful history matching and predictions can be obtained.
Look at the Behavior of the Reservoir, Well, and Facilities as an Integrated System
Authors: Cetkovic Ivan 
Published: December 2007

Abstract
A tool that enables full field economic optimization, driven by gas and oil prices and costs of equipment operation such as compressor fuel gas, water disposal or electrical power generation has become a critical feature. An integrated model helps the production engineer to evaluate and design surface equipment where the behavior of the reservoir and wells are been considered at the same time. These mean that any change on pressure, volume or temperature on the surface conditions will affect the wells and reservoir behaviors and vice versa. If we project this to all the phases of the field life, from planning through development and operations, the need of an Integrated Model becomes more critical.
Common questions from reservoir engineers of what the impact would be of increasing choke diameters, changing artificial lift methods, decreasing separators pressures or installing compression could be answered with an integrated subsurface-surface model. On the same way, questions from operational engineers of what the impact would be of drilling new wells, stimulating the reservoir or implementing a secondary recovery could be answered with a model that looks at the behavior of the reservoir, well and facilities as an integrated system.
Case Study: Mixing Proppant Sizes To Control Pressure-Dependent Leakoff
Authors: Cote A. J. , Crawford K. A. , Nguyen T. H. 
Published: December 2007

Abstract
One of the main factors affecting fracture treatment completion in the Cardium formation in North West Central Alberta is PDL. PDL is determined from minifrac analysis completed prior to the main treatment. PDL can be treated and controlled with a combination of increased fluid rates, additional 50/140 proppant (100 mesh) in the pad and increased gel loadings. Yet in certain areas even these precautions will not achieve successful placement of job design or effective fracture properties.
Common practice is to design for 80 to 100 Tonnes of ceramic proppant into each of these reservoirs, with an additional 5 to 7 Tonnes of 50/140 proppant in the pad to control PDL. In most areas this works effectively for controlling the competing fracture leak-off during the treatment. In the Northwestern Alberta Cardium area this approach has not been as successful and has caused concern about total proppant placement.
An alternative approach for controlling fluid leak-off during the treatment has been to mix in a small amount (usually 5% by weight) of 50/140 proppant with the ceramic proppant in the early stages of the treatments to control the fluid leak-off in these areas. Treatment design engineers recognize the fracture conductivity issues caused by mixing different mesh sizes. However, utilizing this approach has resulted in full job completion and this paper will discuss the specific treatment designs required to drastically limit fracture treatment screen-outs.
Aluminum-Based HPWBM Successfully Replaces Oil-Based Mud to Drill Exploratory Well in the Magellan Strait, Argentina
Authors: Ramirez Mario A. , Benaissa Saddok , Ragnes Gerald , Almaraz Angel 
Published: December 2007

Abstract
Traditionally, Oil Base Mud (OBM) has been used by a major operator to drill horizontal wells in the Magellan Strait, Argentina. The operator was faced with additional challenges when drilling an exploratory well due to environmental concerns in a highly sensitive area and evaluation problems related to the use of OBM. Significant advances in water based drilling fluid design in the recent years have allowed water-based drilling fluid performance to approach that of OBM. This presented the operator and drilling fluids supplier with the opportunity of evaluating the application of water base drilling fluid on this well. The planning stage included laboratory testing, review of historical data and an evaluation of experience with similar shales in the area. A high performance water base drilling fluid containing both clay and shale stabilizers, an ROP enhancer and sealing agents was selected to drill the well.
This paper presents the laboratory and field data generated during this project. The well was drilled through notoriously troublesome shales to total depth without the wellbore stability problems associated with more conventional water based muds. Gas kicks were controlled with no fluid solubility problems and the fluid exhibited excellent properties even when pressure parameters escalated higher than planned, requiring a higher mud density and high degree of temperature stability. The operator's expectations were met in this very difficult well including minimization of bit balling, near gauge hole and improved ROP in conjunction with optimum hydraulics.
The evidence gathered on this project shows that a properly designed water base mud is a viable alternative to OBM in areas where environmental restrictions and formation evaluation problems are a concern.
Sustainable Deployment of Geomechanics Technology to Reducing Well Construction Costs
Authors: Mody Fersheed K. , Tare Uday , Wang Gary 
Published: December 2007

Abstract
Over the past two decades the Geomechanics community has made substantial contributions to the petroleum industry in reducing well construction costs, maximizing production and increasing the life of the well. Borehole (in)stability, lost circulation, stuck pipe, sand production, casing collapse, well failures, and sub-salt related issues are real and can happen unannounced when we are not vigilant and proactive in avoiding them. Prevention is always better than the cure and we all should strive towards preventing these geomechanics related non-productive time (NPT) crises. This paper will be focused on the sustainable technology deployment to bridge the gap and realize the rewards associated with it.
The technical issues that are addressed in this paper are:
Deployment of technical resources to solve borehole (in)stability-related problems, which cost the industry billions of dollars. Using the right resources (i.e., man power, budget, data, etc.) to bridge the gap. However, in order to bridge the gap, geomechanics technologists should be more proactive in capturing the value of technology successes and continuously educating management about the value it creates.
In summary, the industry cannot afford to lose billions of dollars on geomechanics-related NPT and associated lost revenue. Hence, it is critical to manage the available geomechanics resources in the optimum manner. It is important to identify challenging wells and get the right geomechanics resources committed. This commitment needs to be made early in the planning stage of the well construction, and sustained throughout the well delivery cycle. The paper will describe how geomechanics related technology deployment has saved millions of dollars in reducing NPT and achieving business objectives.
PDC Bit Designed for High Lateral and Torsional Stability Significantly Improves Rotary-Steerable Performance in the Middle East
Authors: Barton Steve , Carrington Dominic , Clegg John , Chia Christopher , Garkasi Ali 
Published: December 2007

Abstract
Historic performance in slim hole rotary steerable (RS) applications in the Middle East was held back by severe torsional and lateral vibration issues. A new family of slim hole polycrystalline diamond compact (PDC) bit designs, specifically matched to the rotary steerable systems (RSS) used, has resulted in a dramatic improvement in performance.
The use of mathematically modeled bit performance indices has resulted in a significant improvement in RSS and bit performance while drilling harsh environments in the Middle East where lateral and torsional vibration events are severe. The bit design in question was further optimized by including design characteristics specifically targeted at reducing torsional events. Further, bit hydraulics have been optimized to minimize erosion and maximize borehole quality while matching system operation requirements.
Case studies are presented clearly demonstrating runs with superior performance in the Kingdom of Saudi Arabia (KSA). The field trials clearly demonstrated that significant reduction in torsional vibration and improved side cutting led to superior dogleg achievement. Improvement in lateral stability and resultant bore hole quality led to extended bit and tool life, thus notably improving penetration rate.
The paper concludes that significant performance increases can be achieved by matching the bit design to the RSS, the well geology and the well trajectory. This has resulted in advances in slim hole drilling.
A New Method of Sand Control: The Process and its First Field Implementation
Authors: Aggour Mohamed A. , Abu-Khamsin Sidqi A. , Osman El-Sayed A. 
Published: December 2007

Abstract
A new method of sand control 1,2, which was earlier developed and tested in the laboratory, has been implemented and evaluated in the field. The method is based on a low-temperature oxidation process where a hydrocarbon fluid wetting the sand grains is oxidized resulting in a coke-like solid substance that cements and consolidates the sand grains.
Laboratory development work involved first a series of experiments on small loose-sand packs with the purpose of investigating the effects of control parameters on the quality of sand consolidation and determining the optimum process conditions. Employing the optimum conditions, the process was then tested on a full-scale wellbore model resembling specific actual field conditions. The results of this development work proved that the new method is viable and is potentially superior to existing sand control methods.
The new process was then designed for field-scale applications and was implemented on a well with potential sand production problem. The well was flowing initially at low rates between 200 to 400 bpd and was cutting little sand. Other wells in the field producing at higher rates were experiencing major sand production problems. Following treatment of the well with the new process, the well was produced with ESP at a rate of 4000 bpd without sand production. Close monitoring of the well for more than three months showed no significant rise in sand production.
The Challenges of Deviated Wells
Authors: Krüger Christian 
Published: December 2007

Abstract
A revolutionary intervention technique has emerged allowing mechanical manipulation in horizontal wells in combination with field proven Well Tractor® technology.
As Well Tractor® technology has evolved and confidence has increased in the technology during the last few years, the application of a cost-effective method for opening (and closing) of specific down hole hardware (i.e. valves) as an alternative to existing technologies has emerged. The technology is particularily applicable on offshore installations where the logistical limitations are a major consideration. This article will describe the subsequent applications and the process of developing the technology further.
Tractoring eliminates the constraints of traditional wireline operations by extending the reach of the wireline into the horizontal part of the well and thereby allowing operations to be conducted over the entire length of the wellbore and, if necessary, in a rig-less environment. Additional benefits gained are the elimination of mobilizing heavy equipment, which in turn reduces the number of personnel required to run the operation but most significantly reduces the operational exposure to related safety risks. Furthermore, the equipment required is logistically easier to handle and rig-up time is considerably reduced compared to alternative technologies while providing value-creating solutions.
This paper will present the benefits of wireline interventions, particularly in deviated and horizontal wells, the tractoring solution and case histories exemplifying the advantages of this technology.
Borehole Shape Characterization with Azimuthal LWD Measurements: Evaluation, Applications, and Limitations
Authors: Butt P. , Fareed A. , Ma S. M. , Al-Hajari A. A. 
Published: December 2007

Abstract
Caliper is a fundamental measurement of wellbores. It has significant impacts on decision making regarding well completion and monitoring operations. Traditional Calipers are measured mechanically, thus can not be performed while drilling since they will not be able to survive the harsh conditions of drilling while the bottom hole assembly (BHA) rotates. With logging while drilling (LWD) measurements, several methods have been developed over the years to derive borehole calipers or hole shape indicators from LWD logs. In this paper, we will compare the LWD derived calipers with that obtained from wireline (WL) and summarize the developments, utilizations, and limitations of LWD derived calipers. Factors affecting LWD calipers will also be discussed to help operation petrophysicists for better log data quality control.
Examples will also be shown for using LWD calipers to identify borehole washout, elipticity, breakout, and spiral-hole conditions. Knowing these borehole conditions in real time can help to make action plans to improve drilling practices and reduce drilling risks. After drilling, LWD calipers are used to correct LWD logs for borehole size effects and guide well completions.
Composting: Bioremediation of Soil Contaminated With Weathered Hydrocarbons
Authors: Cecilia Medaura M. , Paula Balla M. , Gutierrez Pablo A. , García de Salamote Inés E. , Garcia Torres Tristán P. , Monzón Azucena , Ercoli Eduardo C. 
Published: December 2007

Abstract
The aim of this work was to evaluate the composting technology in the treatment of soils contaminated with weathered hydrocarbons and drilling cuttings commonly placed in repositories under specific regional conditions.
The composting technology to remediate contaminated soils, consists in the addition of organic material and periodic aeration so that the biodegradation of hazardous organic pollutants and organic matter is favored in a simultaneous process.
In November 2005, a pilot experiment was set up on a location owned by RepsolYPF in the Province of Mendoza, Argentina. Ninety cubic meters of soil contaminated with hydrocarbons were treated under three experimental conditions: two windrows for treatment A (contaminated soil + goat manure, a by-product of the farming activity of the region); two windrows for treatment B (contaminated soil + goat manure + sawdust + sulphur); and two control windrows for treatment C. All the treatments had an aeration system which guaranteed the aerobic process.
Five samples were taken throughout six months of treatment. The variables analyzed were soil physical and chemical parameters, hydrocarbons concentration, microbiological studies and ecotoxicological tests.
The results are encouraging concerning the quality of treated soils: there was a decrease of the toxicity in treatments A and B, an increase in the microbiological diversity, especially for the fungi group, a stimulation of the biological activity (nitrification, humic acid content) and a decrease in the hydrocarbon concentration.
Treatment B turned out to be the most efficient way to obtain a high quality soil. This final product will be used as soil amendment in a well site restoration.
Successes in Curing Massive Lost-Circulation Problems with a New, Expansive LCM
Authors: El-Sayed Mahmoud , Ezz Ahmad , Aziz Moataz , Waheed Arshad 
Published: December 2007

Abstract
The operator controlled losses and a significant salt water kick in a deep gas well using a new dual-action lost-circulation material after fighting losses for 10days. Severe losses were experienced while drilling the Miocene age (Qwassim and Sidi Salim) formations in the Nile Delta region of Egypt. The mud weight was increased to 15.3+ ppge based on pore pressure response until losses started to occur. The losses got beyond 150 bph which hampered operations to drill ahead. Several attempts to cure losses with various commonly used lost circulation formulations were not successful and the choice was either to run casing earlier than planned and compromise the final hole size or attempt a new approach to controlling losses.
This paper will discuss the new approach applied in controlling lost circulation. It involves the use of a "dual-action LCM" that contains multiple-sized particles to enhance fracture tip screenout, along with a synthetic polymer that hydrates in water. When mixed with fresh water and spotted downhole, the polymer can swell up to 400 times its original size. The effectiveness of such treatments help alleviate a lot of the industry troubles by addressing revenue loss from huge mud losses and the non-productive time spent with the rig not drilling ahead.
Custom Designed Water-Based-Mud System Helped Minimize Hole Washouts in High-Temperature Wells: Case History from Western Desert, Egypt
Authors: Bakly Osama , Samir Ahmed 
Published: December 2007

Abstract
It is a common occurrence worldwide to have hole washouts while drilling with water-based mud. There are several reasons for this and until a concerted effort is taken to address the issue, such holes are bound to develop. Some of the problems that large washed-out holes cause are poor hole cleaning while drilling the hole, increased chances of stuck pipe, poor wireline log quality, bad zonal isolation after cementing primary casing strings, and loss of production due to inadequate zonal isolation.
This paper discusses custom-designing water-based systems to address the problem of washed-out holes and wellbore stability. It details the laboratory testing performed on cores and drill cutting samples from the drilled intervals to assess the suitability of appropriate chemicals. The primary study concentrated on understanding the shale inhibition process using water-based fluids. The mineralogical compositions of the shales from the drilled areas were analyzed and tested with various base fluid types and additives.
The recommendations generated from these studies were implemented in high temperature wells drilled by this operator. The results obtained from drilling these wells have been reduced hole wash-outs and stable wellbores.
According to conservative estimates, the problems resulting from shale instability costs the petroleum industry over half a billion dollars per year. The learnings from this paper should help other operators overcome such issues and cut down on non-productive time and expenditures.
Effect of Water Injection on Sand Production Associated with Oil Production in Sandstone Reservoirs
Authors: Essam I. , Wally A. 
Published: December 2007

Abstract
Sand production is a serious problem in many oil and gas assets worldwide. It can affect production rates; it can damage downhole and subsea equipment and surface facilities. Unconsolidated sandstone reservoirs the most susceptible to sand production, which may starts during initial inflow or later, when water breaks through.
Pressure maintenance techniques such as water injection are among the most widely applied secondary recovery processes. When waterflooding is used, early breakthrough at the production well may occur due to reservoir heterogeneity.
There are several possible reasons that may account for rock weakening after water injected water breakthrough:
Chemical reactions between water and rock solids; The changes of surface tension and capillary force; Seepage force resulted from water pressure gradient; Plugging parts of the pay zone.
Based on the actual production history data of Belayim Field wells, which are presented and discussed in the present work, sand production problems detected after salinity of produced water decreased and static bottom hole pressure increased due to water injection effect.
Guidelines to optimize the water injection technique were proposed in the present work as the follows:
Appling compatibility test between formation water and injected water. Sand control technique should be applied or Flow rate reduction after injected water breakthrough. Continues water cut percent monitoring. Appling sand production monitoring and prediction program.