bluuebunny/crossref_metadata_2025_split huggingface dataset:
Surge and Drag Analysis for Extended Reach Casing and Casing Flotation Operations With Centralizers: A Design Challenge?
Authors: Samuel G. Robello , Mason Colin J. 
Published: December 2007

Abstract
Refining advanced technologies for the successful completion of wells is paramount in high-risk, high-cost environments. Challenges are associated with complex well architectures and with the successful completion of wells deploying conventional or floated casing or liner strings. A key part of the design process is to be able predict both maximum downhole surge pressures and dynamic and static friction effects. The analysis also needs to take into account the impact of using centralizing devices. Understanding these effects during both casing running and reciprocation is important so that appropriate operational decisions can be made. Specific challenges are associated with running liners through casing strings or hole sections with limited annular clearance.
Centralizers are primarily installed on a casing string to provide adequate stand-off for primary cementing operations; however they are also sometimes used to aid in the deployment of casing strings. To achieve adequate stand-off, calculations are performed to determine the number of centralizers, their placement, and spacing frequency. Drag modeling is performed to ensure that the casing string will reach its target depth. This requires predictions of both static and dynamic drag effects that take into account the impact of centralizers and surge pressures on drag. In cases where non-rigid centralizers are used, conventional torque and drag models underestimate frictional drag effects. Similarly it is considered that steady state surge models under predict maximum surge pressures.
To address these concerns both improved models and comprehensive analysis is required. This paper describes the analytical models that are used to incorporate additional forces associated with centralizers. Both conventional and floated casing running scenarios, especially in close tolerance extended reach wells, are considered.
New Developments in Nucleation Theory and Their Impact on Natural Gas Separation
Authors: Kalikmanov Vitaly , Betting Marco , Bruining Johannes , Smeulders David 
Published: December 2007

Abstract
Conventional separators in the oil industry use a feed of oil and gas in two-phase multi-component equilibrium. Recently a new concept of separators has been introduced which can be fed with a single-phase gaseous mixture. The separator combines a quasi-isentropic expansion of the gas during which liquid droplets are formed by the nucleation process and a gas-liquid cyclonic separator. The performance predictions of such a separator depend critically on an adequate description of nucleation phenomena. For a large number of practical cases the Classical Nucleation Theory is very inaccurate. The recently proposed Mean-field Kinetic Nucleation Theory yields quantitatively accurate predictions of nucleation behavior of various microscopically diverse substances. An important advantage of non-equilibrium separation is the minimal use of chemicals and absence of regeneration systems, as opposed to conventional separation methods such as glycol contactors or silica gel towers.
Imposing Multiple Seismic Inversion Constraints on Reservoir Simulation Models
Authors: Kalla Subhash , White Christopher D. , Gunning James , Glinsky Michael E. 
Published: December 2007

Abstract
Well data reveal reservoir layering with relatively high vertical resolution but are areally sparse, whereas seismic data have low vertical resolution but are areally dense. Improved reservoir models can be constructed by integrating these data. The proposed method combines stochastic seismic inversion, finer-scale well data, and geologic continuity models to build ensembles of geomodels.
Stochastic seismic inversions operating at the mesoscale (≈10 m) generate rock property estimates that are consistent with regional rock physics and true-amplitude imaged seismic data. These can be used in a cascading workflow to generate ensembles of fine-scale reservoir models, wherein each realization from the Bayesian seismic inversion is treated as an exact constraint for an associated finer scale stochastic model. We use two-point statistical models for the fine-scale model, modeling thickness and porosity of multiple facies directly. The update of these fine-scale models by the seismic constraints yields highly correlated truncated Gaussian distributions. These generate potentially rich pinchout behavior and flexible spatial connectivities in the fine scale model.
The seismic constraints confine the fine-scale models to a posterior subspace corresponding to the constraint hypersur-face. A Markov Chain Monte Carlo samples the posterior distribution in this subspace using projection methods that exploit the reduced dimensionality that comes with the exact constraints.
These methods are demonstrated in three-dimensional flow simulations on a cornerpoint grid, illustrating the effects of stratigraphic variability on flow behavior.
Measurement and Calculation of Key Events During the Plunger Lift Cycle
Authors: Lea James F. , Rowlan O. L. , McCoy J. N. 
Published: December 2007

Abstract
As a normal gas well's production rate declines below a critical limit, produced liquids begin to collect in the tubing or flow passage, and the gas flow is further reduced or stopped by additional liquid pressure on the formation. Many authors describe the time when liquid begins to collect in the well as the gas flow has decreased below the critical flow rate, although perhaps more reliably, the production rate will begin to drop below the original decline curve. Popular lift methods for dealing with liquid loading caused by gas rates below critical are: compression, velocity strings, beam pumps and other pumps, surfactant injection, and plunger lift. Plunger lift is a popular method for dewatering gas wells due to the low initial installation cost and due to low operation cost by using the well's stored energy to dewater the well. Plunger lift is one of the primary artificial lift methods used to overcome liquid loading problems in gas wells.
A few simple rules-of-thumb are frequently used in the initial configuration of the plunger lift installation. These rules-of-thumb have been translated into mathematical algorithms to allow the operator to estimate the rise velocity of the plunger, the liquid slug size per cycle and time period intervals for the plunger cycle. Algorithms are used in this paper to calculate timings for events during the plunger lift cycle, and the times are compared to key events determined from measurements acquired at the well. For example, the minimum shut-in time calculated from one algorithm is compared to the precise time measured for the plunger to fall from the surface to the bottom of the well. Using the measured tubing and casing pressures and plunger location during the cycle along with other well parameters, the operator can verify the plunger lift system is operating as desired. Both measured plunger lift performance data and calculations from the algorithms guide the operator to effectively analyze, adjust and optimize the plunger lift installation. Acquired data from various plunger lifted wells are used to validate the algorithms presented.
Information presented in this paper will assist the operator of gas wells who is suffering from gas flow rates below critical and is using plunger lift to alleviate the corresponding liquid loading problem.
Stimulation Flowback Management: Keeping a Good Completion Good
Authors: Crafton James W. , Gunderson Dan 
Published: December 2007

Abstract
All oil and gas well stimulation processes, and particularly hydraulic fracturing, require a post-stimulation flow period to prepare the well for long-term production. Operators and service companies have begun to recognize this as one of the most critical times in the life of the well. Intensive management of the flowback and evaluation of the available performance information during flowback can yield significant improvement in the well's long-term performance. That information also provides the basis for improving future stimulation and well management strategies. For example, excessive flowback rates are known to cause proppant flowback or fracture collapse in a fracture stimulated well. Postponement of flowback after the stimulation and shut-ins once production is established do impact future performance.
Proper data collection and interpretation provide the ability to interpret the characteristics of the placed fracture and the impact and management of various flowback procedures. Specifically, it is possible to assess the conductivity of the proppant bed, its propagated length and the impact of on-set to multi-phase flow. If the flowback and data collection are properly conducted, the early data will also contain information about the characteristics of the reservoir and fracture. With this in mind, the types of data, acquisition and interpretation methods are shown for three field examples.
Reviving the Mature Handil Field: From Integrated Reservoir Study to Field Application
Authors: Herwin Henricus , Cassou Emmanuel , Yusuf Hotma 
Published: December 2007

Abstract
The Handil field, discovered in 1974, is a giant mature oilfield located in the Mahakam Delta, Indonesia. The field consists of 555 accumulations and was developed by more than 350 wells with conventional oil recovery methods: natural depletion and peripheral water injection. After many reservoirs have been water-flooded, in order to recover the tertiary oil, EOR lean gas injection project was started in November 1995 on five reservoirs. The project was successful and extended to the other six reservoirs in 2000. However, the field production continued to decline from 200,000 BOPD in the late seventies to 12,500 BOPD in 2003.
An integrated study on the largest EOR reservoir was performed to assess the projects' performance, including 3D geo-modeling, reservoir simulation and chemical tracer injection. The study permitted to track the main effects of the gas injection and define reservoir management guidelines for the other lean gas injection reservoirs.
In the same time, dynamic synthesis has been performed in all accumulation in Handil Field with objective to identify potential "by-passed" oil and un-drained areas. Following the study, an intensive Light Work Over campaign has been launched and three pilot wells, each with different completion type, have been successfully put on production and became the model for the next Handil development wells; horizontal well equipped by gas lift to recover viscous sandy reservoir in very shallow zone, gravel pack equipped by ESP to recover sandy reservoirs in shallow zone and monobore multi-target well equipped by gas lift to recover reservoirs in main zone.
The production has been increased by nearly 100 percents, from 12,500 BOPD in 2003 to 23,000 BOPD nowadays. Integrated reservoir study and the successful application of Light Work Over and Infill Well to recover "by-passed" oil and un-drained areas, supported by EOR techniques to maintain the reservoir pressure and sweep the tertiary oil, become the key elements to revive the mature Handil Field.
Formation Pressure while Drilling Utilized for Geosteering
Authors: Neumann P. M. , Salem K. M. , Tobert G. P. , Seifert D. J. , Dossary S. M. , Khaldi N. A. , Shokeir R. M. 
Published: December 2007

Abstract
Placement of a horizontal power water injector well in close proximity above an impermeable, undulating, heavy oil and tar layer poses a unique geosteering challenge. The uncertainty was to determine at what vertical depth fluid mobility stopped and heavy oil began in the high porosity reservoir. The heavy oil layer is undetectable with conventional real-time LWD measurements. Furthermore, new technology devices such as Formation Pressure While Drilling (FPWD) and NMR While Drilling can be used to detect heavy oil but only after the BHA has entered the layer. A technique of combining FPWD with LWD/MWD provides the best opportunity to identify and steer away from immobile layers, minimizing the risk of completing an injection well in intervals without injectivity.
The FPWD tool was placed behind the MWD/LWD assembly. LWD data was used to provide the information to locate ideal testing depths. This prevented taking "blind" pressure readings in low porosity/low permeability intervals during drilling operations. Conclusions from the pressure drawdown and build up profile, combined with pressure and mobility data, were used to make the decision whether to continue on the current well path or to consider a directional change.
Zones with limited injection potential were avoided after initial low mobility detection by the FPWD tools. Repeated "lost-seal" or "tight" readings from the FPWD tool in high porosity zones are excellent indicators that the bottom hole assembly has entered an impermeable layer in a highly porous reservoir. Timely communication of low-to-no mobility readings generated the opportunity to geosteer the well back into permeable reservoir to meet the well placement objectives.
This paper covers two case studies demonstrating both entry into and steering away from impermeable heavy oil layers in addition to discussions on the planning and geosteering operations.
Operation Support Centers - Real Time Drilling Optimization and Risk Mitigation
Authors: Monden Takashi , Chia Christopher R. 
Published: December 2007

Abstract
Real time connectivity from the rig to the office is becoming the norm for many operations today. The real time operation support center (OSC) is the hub of these activities in town where domain experts, data interpretation experts, and drilling experts alike can be involved directly in data-centric collaboration and critical decision making. Having the ability to move the point of decision making from the point of data acquisition to the OSC intuitively provides the capability for more effective drilling optimization and the direct saving of non-productive time through risk mitigation.
A series of real case studies that show the range and scale of measures, and the interpretive actions that can be taken to optimize drilling and minimize downtime. Direct improvements in drilling rate of penetration through advanced software modeling of drilling parameters will be shown. These cases involve both the reduction of shock and vibration to the drilling assembly, thereby transmitting more of the energy in the system to the bit face, as well as the direct rate of penetration improvements through balancing weight on bit and surface RPM for each drilling system. Other cases will demonstrate improved well placement in the reservoir through the combination of monitoring the drilling parameters in conjunction with the real time data from the formation evaluation downhole tools. Direct troubleshooting of downhole tool problems relating to changes in downhole conditions will also be presented, and in many cases this can save an unnecessary trip out of hole.
Together, these case studies will show that significant value can be achieved by maximizing the effectiveness of the OSC, and by fully integrating real time quality and decision making procedures into all drilling operations. It can further be concluded from these case studies that this value can be measured, and can truly create a step change in performance. These improvements can be translated directly into lower cost per foot, and better hole quality, in addition to reduced lost in hole and therefore better equipment utilization.
Improving Local Bentonite Performance for Drilling Fluids Applications
Authors: Al-Homadhi Emad S. 
Published: December 2007

Abstract
Drilling fluid is a vital element of the drilling process. Any drilling fluid must have common properties that facilitate safe and satisfactory completion of the well.
The main component of water base mud is clay (mostly bentonite). The present consumption of bentonite clay in the drilling operations in Saudi Arabia alone can reach over 100 thousands tons a year and all of it is imported from USA. This trend is expected to continue as drilling activity increases. The large consumption and the high importation cost of this material lead to an attempt to find a local substitute.
Clays in Saudi Arabia are represented by numerous commercial stocks. The use of these local clays in the drilling activities can save a huge amount of hard currency that otherwise would be spent on importing it from abroad.
Several attempts were made to investigate shale outcrop precipitates in the kingdom. This work focuses on the possibility of the utilization of local bentonite clay minerals as a basic material for drilling fluids used to drill oil and gas wells. The only known bentonite outcrop in the kingdom is in Khulays area, 70 km north Jeddah adjacent to Makkah-Madinah road.
API specifications for acceptable drilling mud was the base for evaluating the local bentonite The properties of the local mud can be improved economically by adding some cheep materials to the prepared mud to enhance its viscosity and filtration loss (such as CMC, Drispac polymer, and bentonite extenders). Also shearing speed can be used as an enhancement method to improve the dispersion rate of the clay suspension, and hence increase viscosity and decrease filtration loss. But the used shearing speed should be limited to a practical and economical speed.
The bentonite extender can be either a salt or a polymer, it enhances viscosity buildup by slightly flocculating the bentonite suspension. Sodium carbonate is an example of a salt that can be added as an extender. Soaking raw bentonite with a solution of sodium salt resulted, through ion exchange, in a higher sodium bentonite content. More effective extenders than inorganic salts are the high molecular weight linear polymers.
Pore Network Modeling: A New Technology for SCAL Predictions and Interpretations
Authors: Suicmez V. S. , Touati M. 
Published: December 2007

Abstract
There have been recently substantial advances in Pore Scale Physics Discipline. These advances can now be used for the benefit of special core analysis (SCAL) measurements and interpretations. This paper is devoted to explain these improvements from two perspectives: (i) Pore scale imaging and network extraction (ii) Fluid flow modeling applied on the extracted networks in order to predict some key petrophysical properties (capillary pressures, relative permeabilities).
We use either thin sections or X-ray microtomograhy (micro-CT) to analyze rock cuttings of sandstones from Saudi Arabian oil and gas fields. These cuttings are a few mm across and are imaged with a resolution of 3 to 12 microns. Hence, the details of the three-dimensional pore space can be clearly seen. A maximal ball algorithm1,2 is used to extract a topologically equivalent pore-throat network: the largest inscribed spheres in the pore space representing the pores, with throats representing the connections between them.
In parallel to this algorithm, thin section images are utilized to build 3D equivalent images, reproducing porosity by a similar spatial variation of the grain sizes obtained from the thin sections. This has been done through the so called process based technique3 which is based on honoring the geological depositional mode of the rock.
The final aim is to input these network models into porescale fluid flow simulators to predict macroscopic properties such as relative permeability and capillary pressure. Blind tests are envisaged to compare the measured petrophysical properties and their corresponding numerical estimations.
This acts as a valuable complement to special core analysis, enabling predictions of properties – such as three phase relative permeabilities and the impact of wettability trends − outside the range probed experimentally.
A New Hybrid Inverse Modeling Method for Water Quality Monitoring Using Remotely Sensed Data
Authors: Shahraiyni H. Taheri , Schaale M. , Shouraki S. Bagheri , Fell F. , Fischer J. , Taheri M. , Preusker R. , Tajrishy M. , Vatandoust M. , Shahraeini M. Taheri , Sani P. Navi , Taherishahraini Z. , Khodaparast H. 
Published: December 2007

Abstract
All of the man-made objects and anthropogenic activities related to the oil industries in water bodies (e.g. drilling, equipment installation, construction of oil platforms and especially oil spillages) have environmental impacts on water ecosystems. The assessment of oil field operations and oil platforms impacts on water quality have become a necessity throughout the world. Phytoplanktons have the lowest trophic level in water environment; therefore the life of all of the other marine animals is highly relevant to phytoplanktonic population. Hence it seems necessary to monitor the spatiotemporal effects of different activities and events, related to oil industries on phytoplanktons. Chlorophyll is an indicator of phytoplanktonic biomass. Area-wide monitoring of Chlorophyll using conventional in-situ measurement methods is expensive and time consuming. However remote sensing measurements can provide a complementary tool for chlorophyll monitoring, but the remotely sensed data inherently contain high level of noise and some of the methods are failed in operational application to satellite data for the chlorophyll retrieval and also it is not easy to retrieve chlorophyll of noisy remotely sensed data in optically complex waters. Therefore robust and accurate inverse modeling methods for the chlorophyll retrieval of satellite data are needed. The aim of this study is to develop an innovative robust and accurate inverse model for the chlorophyll retrieval of Caspian Sea from MERIS (MEdium Resolution Imaging Spectrometer) data. We developed a new hybrid inverse model using the integration of ALM (Active Learning Method) and ANN (Artificial Neural Network) inverse models. The results of this study showed that it is very robust to noise and also demonstrated that it is very useful model for chlorophyll retrieval of remotely sensed data in the coastal (high chlorophyll concentration) and open sea (low chlorophyll concentration) waters. The main outcome of this research is an automatic code which is able to process satellite images automatically and enables robust water quality monitoring of different water bodies.