bluuebunny/crossref_metadata_2025 huggingface dataset:
Phased-Development Strategy to Mitigate Subsurface Uncertainties and Risks in Developing a New Gas Field: A Case Study in the ADCO Fields, UAE
Authors: El Bahri Sami , Al-Shaarawy Osama , Chouaibi Mohieddine , Ghorayeb Kassem , Amanov Batyr , Stojic Slobodan
Published: December 2014

In a new field development plan (FDP), it is essential to identify and assess both static and dynamic reservoir uncertainties. Therefore, an integrated field development study was conducted on multilayered, thin, and relatively tight rich gas-condensate reservoirs in one of the Abu Dhabi Company for Onshore Oil Operations (ADCO) fields. The study identified new potential areas where very limited data were available. Therefore, drilling appraisal wells was essential to confirm the potential of these areas, narrow down the uncertainties, and minimize the development risks.

The phased field development strategy made it possible to appraise the new identified potential areas before embarking on facility construction and drilling development wells. The phased-development plan consists of two major phases:

Phase I

•Drill appraisal and development wells onshore and on existing artificial islands.

•Drill appraisal and development wells by extension of existing artificial islands.

•Collect data, mainly consisting of coring and special core analysis and additional fluid sampling.

•Use long-duration tests to assess performance and sustainability of each reservoir.

Phase II

•Construct new artificial islands in confirmed areas.

•Drill development wells on new artificial islands.

The phased field development strategy takes advantage of a continually changing and improving reservoir model in addition to accelerating the time of first gas production and project revenue and minimizing the associated development risk.
Numerical Temperature Modelling for Quantitative Analysis of Low-Compressible Fluid Production
Authors: Aslanyan Arthur , Aslanyan Irina , Salamatin Andrey , Karuzin Andrey , Fesina Yulia , Zaripov Ilnaz , Skutin Vasiliy , AL Ghafri Zaaima , AL Yarabi Mohamed , AL Maharbi Abdulaziz
Published: December 2014

Temperature logging is an efficient technique to locate inflow intervals in the reservoir, evaluate inflow rates in them and the drawdown pressure that creates temperature disturbance, detect cross-flows in the wellbore and/or behind casing and check for casing, tubing and the bottom-hole leakages. Temperature logging can detect wellbore flows with rates way below the mechanical spinner's threshold. Another impressive application of temperature logging is picking flow zones behind unperforated casing that develop through behind-casing channelling. Such findings can be verified or discarded through numerical simulation of temperature logs. This paper presents the TSMp solver module of the TERMOSIM simulator that can reproduce complex hydrodynamic flow patterns and the associated thermodynamic effects, taking place during fluid flows through a multi-layer reservoir towards the wellbore and their blending in it, including heat exchange between reservoir and wellbore flows and the surrounding rocks.

The TSMp solver takes into account possible inter-reservoir communications both inside and outside casing caused by the pressure difference between formation units, as well as short-term and long-term lateral flows that can disturb the temperature at any depth, and calculates fluid rates for each formation unit and temperature profiles for the wellbore and for any distance from it.

This paper describes the general physical and mathematical models and user interface of the TERMOSIM TSMp simulator for producers and presents modelling results for two production wells of Oman. For each well, the TSMp simulator has been employed to create a best-fit individual thermohydrodynamic model and match downhole pressure and temperature records for different production rates. The well log analyses based on temperature modelling presented in these case studies open the way to (a) identify actual reservoir inflow intervals, (b) evaluate formation pressure in flowing units, (c) evaluate inflow rate from each flowing unit and (d) distinguish between wellbore cross-flows and behind-casing channelling.

The case studies presented in this paper are focused on low-compressible, mostly single-phase fluids with high water or oil and low free-gas contents (while multiphase flows with abundant free gas will be covered in a separate paper).
A New Method for the Characterization of Heavy Oil and Bitumen using Distillation Curve Data
Authors: Azinfar Bahareh , Zirrahi Mohsen , Hassanzadeh Hassan , Abedi Jalal
Published: December 2014

Fractionation and characterization of heavy oil and bitumen are essential steps for phase behaviour modeling and the simulation of bitumen production, refining, and upgrading processes. Typically, the bitumen is divided into several pseudo-components in order to tune an equation of state (EoS) and then utilize it for the process modeling and reservoir simulation. The interaction coefficients and critical properties of the pseudo-components are commonly tuned using experimental laboratory oil PVT data. Measuring of this data is very expensive and time consuming, especially for heavy oils. Characterization based on experimental distillation data has the potential to eliminate the need for time consuming laboratory oil PVT data.

In this study, we present an effective model for the characterization of heavy oil and bitumen using experimental distillation data. Batch distillation without reflux is modeled to regenerate the experimental distillation curve using the residue curve map method. The Peng-Robinson equation of state (PR-EoS) and NRTL activity model are applied to calculate the fugacity and activity coefficients in the gas and liquid phases, respectively.

The proposed model was able to accurately regenerate the experimental distillation curve. The properties of the characterized fractions and the binary interaction coefficients obtained from the model were used to estimate solubility of light solvents (CH4, C2H6, CO2, N2) in the Athabasca bitumen. Good agreement between the experimental and the estimated solubilities reveals that the proposed approach is a reliable predictive tool for heavy oil and bitumen characterization.

The proposed model provides an accurate and simple method for characterizing heavy oil and bitumen. The only data required is the experimental distillation curve. Since this model does not require experimental oil PVT data, it can be applied quickly and inexpensively compared to other methods available in the literature. The presented approach will find many applications and has potential to become the superior method for phase behaviour studies of heavy oil and solvent systems.
Challenges on Sampling and Characterization of Heavy Oil in Deep Exploratory Wells: A Field Case Study
Authors: Rajkhowa Anupam , Al-Bader Haifa , Hameed Waleed Ahmad , Al-Nabhan Abdul Razzaq , Subban Packirisamy
Published: December 2014

Exploration activity on heavy oil is steadily gaining momentum in the state of Kuwait. Recently, discovered heavy oil in deeper low permeable Lower Cretaceous reservoir from exploratory wells drilled in two different fields of West Kuwait area at around 11,000 ft. depth. Drill stem testing method was applied to test these exploratory wells. During testing, there was inflow of heavy oil of API 21-22 deg, but the well could not be produced naturally in spite of repeated attempts. Matrix acid stimulation treatment was done to improve the productivity of the reservoir. Well-flowed heavy oil and then gradually ceased to flow. Due to viscous nature, low mobility and low reservoir energy, self-flow could not be sustained. These pose significant challenges for well cleanup, flow studies and collection of representative sample for PVT analysis and fluid characterization.

As no other lifting methods were available, Coiled Tubing was lowered and the well was lifted continuously with nitrogen for cleanup and to assess production behavior. Surface Sampling was not favorable due to mixing with lifting nitrogen gases and only alternative method available was to collect Bottom-Hole Samples (BHS). However, proper cleanup was an issue for sampling operation. Therefore, compositional analysis was done on the lifted sample to quantify the contamination level in the produced fluid before lowering the down-hole sampler in order to capture representative samples. As a result of this approach, representative samples could be captured and fluid characterization could be carried out with quality results which will add value to future reservoir study and modelling. Based on the successful results, it has been planned to use similar approach for sampling in such conditions.

Methodology adopted to overcome challenges faced for sampling and characterization of heavy oil in deep as well as in low permeability reservoirs will be presented in this paper.
A Case Study of Hydraulic Fractures Optimization in Heavy Oil
Authors: Bo Cai , Yunhong Ding , Yongjun Lu , Yonghui Wang , Xin Wang , Chunming He , Liao Wang
Published: December 2014

With high oil demand and prices, and production of most conventional-oil reservoirs in decline, industry focus in many parts of the world is shifting to exploitation of heavy oil, extra-heavy oil and bitumen. Hydraulic fracturing stimulation is also an important technology for some tight heavy oil formations with low porosity and ultra-low permeability in the Songliao and Bo haiwan basin in North China, while application of conventional fracturing technology in the recovery processes of heavy oil reservoir will meet some problems such as high viscosities, poor flow properties and high densities in compared to conventional oil. This paper describes a successful case of proppant fracturing on an ultra-low peameablity and high viscosity (17.6API) sandstone heavy oil reservoir in eastern China. Several technologies including pre-pad fluids, hydraulic fractures numerical simulation for enhancing heavy oil drainage area, tip screen-out (TSO) fracturing in order to improve fracture conductivity, multi-step slurry injection schedule, low damage gel were used.

More than 33 treatments with new technologies in Huabei, Liaohe oil field have been performed with encouraging results, 88.5% efficiency with accumulated incremental oil of 213,050 ton and the average post-fracturing rate reach to 25.9m3/d satisfied as expected, which is three times of before stimulation, while in the past, there were many treatment failures. It has a great significance not only in improving fracturing treatment effect in above mentioned heavy oil formations but also in perfecting low damage fracturing technique as well.
Polymer Flooding for Extra-Heavy Oil: New Insights on the Key Polymer Transport Properties in Porous Media
Authors: Rodriguez F. , Rousseau D. , Bekri S. , Djabourov M. , Bejarano C.
Published: December 2014

Primary cold production in extra-heavy oil reservoirs (7-12° API) is currently a low percent of the OOIP, as for some oil fields in La Faja Petrolífera del Orinoco (FPO), Venezuela. EOR studies are being conducted in order to increase recovery factors primarily in those thin bedded reservoirs which host up to 35% of the OOIP. Thermal EOR is usually the first option implemented to increase recovery. However, thermal methods are not suitable for thin pay zones and involve high water consumption which can create environmental issues. For these reasons, chemical EOR is becoming a feasible tool for mobility control and mobilization of residual oil.

Polymer flooding applied to extra-heavy oil may require rather high concentration polymer solutions. The objective of this study is to contribute to a better understanding of the specific mechanisms involved in this context. Transport properties of polymer in porous media are investigated through a set of corefloods tests performed on model sandpacks, the high permeability (4 Darcy) and the temperature (50°C) being representative of the conditions of the FPO. Polymer transport is analyzed versus injection concentration in terms of the key petrophysical parameters controlling the performance of a polymer flooding operation, namely: retention and inaccessible pore volume, in-depth propagation and injectivity.

Results show that all parameters strongly depend on polymer concentration. Specifically, the concentration dependence of polymer retention, inaccessible pore volume and in-depth propagation behavior cannot be interpreted by conventional models. Injectivity is also strongly affected by concentration: both rheo-thinning and rheo-thickening effects become more marked when concentration increases. This set of experimental data are the key for modeling the transport of high concentration polymer solutions in porous media. They also provide direct information needed, through reservoir simulation, to sanction the technical and economical feasibility of polymer flooding for extra-heavy oil.
Using Cyclic Steam Pilot Performance to Address Reservoir Description Uncertainties
Authors: Sanyal Tirtharenu , Waleed Al-Khamees , Abdulraheem Hadeel Faisal , Amal Al-Sane , Abdulla Al-Balam
Published: December 2014

In a thermal Enhanced Oil Recovery project of Kuwait, the static reservoir description uncertainties were identified based on initial static description. The associated development impact and possible risks to the project is then evaluated using a commercial uncertainty analysis tool through simulation studies. Field dynamic testing results from the ongoing Cyclic Steam Stimulation(CSS) pilots and other dynamic testing data were then used to evaluate the static description uncertainties, for an improved reservoir description.

The observation from the study is extremely important in not only having an improved understanding of the reservoir description of the subject field but has wider implications in similar reservoir set ups in other parts of the globe. The observations from the pilot operation and simulation history matching clearly demonstrates that local reservoir set up plays a crucial role in each thermal project and understanding them is extremely important for success of the project. The results of the study demonstrate the importance of integrating dynamic cyclic steam stimulation testing results with preliminary static description, to arrive at an improved reservoir description.

The technology of thermal Enhanced Oil Recovery (EOR) is an old concept but its application in different reservoir set ups give rise to new learning that widens the knowledge base in the industry. The reservoir being developed in Kuwait is considered a challenging one from many of the classical screening concepts. The success of some of the experiments tried in this project and the learning from their success has wider potentials in similar complex thermal developments.
De-risking a Heavy Oil Development - A Case Study of the Bentley Field, UKCS Block 9/3b
Authors: Brennan B. H. , Lucas-Clements C. , Kew S. , Dempsey P. F.
Published: December 2014

The Bentley Field, located on the UK continental shelf in block 9/3b in 110 m of water, contains approximately 900 MMstb in-place of heavy (10 to 12 oAPI) viscous (1500 cP) crude. The field is four-way dip closed at uppermost Palaeocene, lowermost Eocene, Dornoch sandstone level, and covers an area of about 16 Km by 5 Km.

An appraisal programme culminating in the 2012, 9/03b-7, 7Z extended well test (EWT), has addressed the key technical concerns associated with developing the viscous crude in an offshore environment. The programme demonstrated how sustainable commercial flow-rates can be achieved through the selection of a suitable completion design, including a downhole electrical submersible pump (ESP), a downhole diluent injection strategy, and through keeping within an appropriate operating pressure and temperature envelope. It further demonstrated that the movement of water from the underlying aquifer into the production bore proceeds in a predictable and manageable way, that produced water and oil can be separated even though emulsions are created in the ESP, and that water can act as a carrier fluid within the export pipeline.

The information from the EWT has been used to define and de-risk the field development design which is currently estimated to deliver 257 MMstb of 2P Reserves over a 35 year production period. In addition it is estimated that 48 MMstb of 2C Contingent Resources could be commercially extracted beyond the end of the currently planned facilities life. Investigations are underway to accelerate this tail-end production, with initial studies indicating that a polymer flood, enhanced oil recovery scheme, could be attractive.

This paper describes the appraisal programme, the lessons learnt and how these have been applied in designing the field development plan.
Analysis of Heavy Oil Production by Radio-Frequency Heating
Authors: Bogdanov I. , Cambon S. , Prinet C.
Published: December 2014

During last decades the major companies increasingly exploit such hydrocarbon resources as heavy oil, bitumen or oil shale. The production of oil from such reservoirs is frequently done through reservoir heating, most often via steam injection. However it becomes more and more evident that for some cases there exist better suited technologies and one of them is the electromagnetic (EM) heating assisted oil recovery. According to the EM field frequency different physical mechanisms may underlie the heat release. The radio-frequency (RFH) or dielectric heat generation results from rotation with friction of polar molecules in the EM field.

The advantages of the RFH-based technology are related to the in-situ heating and steam generation from the connate water which eliminates the problems associated with low well injectivity, well injection pressure, the water supply and hence, the water treatment etc. They include also the possibility to apply the heating in shallow or thin reservoirs and also in case of initially mobile heavy oil to optimize the production efficiency using both principal production mechanisms: the gravity drainage and the steam drive.

The large-scale RFH models have been recently developed for numerical simulation of realistic EM power distributions. These models provide a means to critically analyze the processes of oil recovery. In the current study we take advantage of two dedicated simulators and the methodology of loose coupling between them to deliver the calculated EM heating power field to dedicated reservoir simulator.

The combination and competition between two principal production mechanisms for different well patterns, spacing and orientation are considered; their influence together with other operational conditions impact on the efficiency and application limits of the oil recovery method are analyzed.

The analysis of different mechanisms of RFH assisted heavy oil production is an important feature in process design considerations.
Modeling Unconventional Recovery of Next Generation (Extreme Heavy Oil) Deep Tar-Mat Reservoir
Authors: Al-Bazzaz W. , AlMansour A.
Published: December 2014

This study models recovery of deep Tar-Mat available in substantial amounts in the Middle Eastern general and in Kuwait in particular as next generation and strategic reserves for extreme viscous and immobile solid-like unconventional oil. The study considers three unconventional different physical models. These physical models' fundamentals are generated, validated and predicted hence formulated using conventional extraction and unconventional geochemistry technologies. The first conventional recovery physical model is the liquid extracts of Saturates, Aromatics, Resin, Resin-to-Asphaltene (RAS) and Asphaltenes yielding unconventional model (RAS Model). The second unconventional recovery physical model is the elemental fingerprinting of carbon, hydrogen, nitrogen, sulfur and oxygen (H/C Aspect-Ratio Model). The third unconventional recovery physical model is the rock evaluation pyrolysis.

In this study, sixty experimental lab data are performed on five fresh tar mat samples. Also three EOR agents are proposed for recovery techniques, toluene solvent, de-ionized water and surfactant-aided de-ionized water. Since four proposed thermal EOR techniques have been used 25°C, 135°C, 225°C and 315°C temperatures for the recovery, all recovery models honor systematic temperature variation for the recovery.

All three unconventional models are laboratory data-driven models, which will attempt to define recovery patterns, quantify novel phenomenon, and develop new relationships. Each physical Model will have the ability to assess the recovery application for this unconventional reservoir. Assessing the recovery starts with unconventional measuring the API density that is less than 5 °API henceforth the viscosity and the mobility of Tar-Mat-solid-like oil. Then monitor the recovery as the type of EOR agent and temperature conditions are elevated during the recovery process. On the basis of recovery findings unconventional models, new tools will be developed for engineers, geologists and oil companies to prospect this strategic reservoir.
Optimized Steam Pulse Injection (SPI) In a Carbonate Reservoir: Issaran Egypt Field Trial
Authors: Rizkallah M. , Alfy S. A. , Basta G. S. , Ghaleb A. A. , Kortam W. T.
Published: December 2014

This paper describes a field trial of an optimized Steam Pulse Injection (SPI) scheme in a heavy oil (10-12O API) dual porosity carbonate reservoir located in Egypt. The field is known as Issaran with approximately 1.2 billion barrels of oil in place. Up dip steam injection in selective wells has been applied since August 2009. The fracture network helps upward distribution of steam, heating of the matrix thus wettability change to water wet and release of oil towards the deeper "drainage off take" points. The steamflooding has worked well until the Instantaneous Steam Oil Ratio (ISOR) was getting closer to uneconomical limits. In December 2013, it was decided to test an optimized SPI scheme in the Upper Dolomite South development (old area). Presently the process is working efficiently with oil being drained towards selective low pressure drainage points and in a calculated fashion using IVRR (Instantaneous Voidage Replacement Ratio) controllers. The SPI scheme calls for "On & Off" injection modes. During the "On Mode" injection proceeds normally in all designated injectors. During the "Off Mode" injection continues in few selected injectors. The "Off Mode" injectors are selected on the basis of controlling IVRR around a fault, known as the "magic fault", with the surrounding wells being target withdrawal points for oil production. SPI was designed to reduce operational costs while also benefitting from the pressure release phenomenon, which releases trapped oil from the matrix towards the fracture system and producing wells. During the first 210 days of field trial approximately 823,610 bbls of steam were saved and the ISOR almost halved. The optimization of the SPI will continue and will undoubtedly allow for the extension of the economical life of the field.
Heavy Oil Quantification Using Nuclear Magnetic Resonance and Elemental Spectroscopy Technologies in McMurray Formation, Mannville Group, Lower Cretaceous
Authors: Bouchou Ramdane , Markovic Milan , Wei Jiang
Published: December 2014

The Athabasca oil sand is one of the three major bitumen deposits in northern Alberta. It contains about 80% of the Alberta total bitumen deposits. The McMurray Formation, Mannville Group, Lower Cretaceous, which contains the Athabasca oil sands bitumen deposit, covers about 46800 square kilometers at an average thickness of 60 meters. The total recoverable reserve is estimated to about 170 billion barrels, which is the second largest oil reserve after Saudi Arabia.

Variation in the formation water resistivity (Rw) and difficulties to accurately estimate the shale volume (Vsh) over the heavy oil zones present a real challenge in water saturation calculation, thus in total reserves estimation. A combination of Nuclear Magnetic Resonance and Elemental Spectroscopy Technologies, with conventional logs, permitted us to quantify the different components of the heavy oil in the reservoir over the McMurray formation.

The technique is to use the clay volume, directly measured with the nuclear spectroscopy tool, to discern the "visible to NMR" heavy oil component from CBW in the 2D NMR analysis. The "invisible to NMR" heavy oil component is estimated using the lithology corrected density porosity and the NMR total porosity. The total heavy oil saturation of one of the five studied wells is compared to core oil saturation and to nuclear spectroscopy oil saturation, diredctly derived from the measured carbon. Excellent matching between the three results is seen.

This approach presents advantages over the classic petrophysical methods, mainly in zones with variable connate water salinity and variable clay minerals. Its application can be extended to any bitumen or heavy oil deposits and will help in reducing coring programs.
Optimal Application Conditions of Steam-Solvent Injection for Heavy Oil/bitumen Recovery from Fractured Reservoirs: An Experimental Approach
Authors: Leyva-Gomez H. , Babadagli T.
Published: December 2014

Although the previous static experiments provided critical information as to the existence of a critical temperature range that yields the maximum heavy-oil recovery during steam/solvent injection, dynamic experiment are needed to account for the relationship between the solvent introduced into the system and heavy-oil recovery.

We conducted a series of dynamic experiments in which liquid (heptane) solvent was injected into a heavy oil saturated rock matrix, surrounded by a fracture with and without pre-thermal injection. Water-wet rock matrix (sandstones) was saturated with heavy oil and placed inside a core holder. Next, the system was placed into an oven and maintained at constant temperature conditions. Then, either hot solvent (superheated to be in vapor phase) or cold solvent was introduced into the system through the fracture at a constant rate. Pressure and temperature was continuously monitored along the core and the properties of oil and liquid condensate from gas produced were measured and analyzed. This scheme was repeated for a wide range of temperature conditions.

The first requirement for a successful application is that the solvent should diffuse into matrix effectively before it breaks through and improves gravity drainage of oil by dilution. The second requirement is solvent retrieval. The retrieval of the solvent during solvent injection phase and post-thermal method (steam or hot-water) injection performed at the near-boiling point temperature of the solvent was monitored. Our results and observations indicate that there exists a critical temperature and injection rate that yields a maximized oil recovery and solvent retrieval.
Comparison Between AMPCP and SRP in a Shaly-Sand Reservoir In Terms of Sand Production
Authors: Alnaqi Yaser , Tohidi Bahman
Published: December 2014

Sand production is considered one of the major problems that would affect the economical value of any EOR project. The produced sand will start to accumulate in the wellbore till it kills the Well. This is done by increasing the pressure drop (both frictional and hydrostatic) in the borehole to a point where no more fluid can be produced. It can also exhibit a mechanical damage to the pipes, chokes, surface facility lines and would require continues cleaning.

There are several sand control equipment that can be installed whether in the wellbore or in the formation itself. However, these sand control equipment not only add a cost element to the whole project, but also most of them reduce the Productivity Index of the well. Consequently more wells need to be drilled in order to compensate the production loss due to the installation of sand control equipment.

This paper examines the effect of using Sucker Rod Pump (SRP) and All Metal Progressive Cavity Pump (AMPCP) on the sand production. Both pumps can handle solids to some degree, however, the mechanism of each pump will affect the building of sand arch and thus will impact the amount of sand volume produced.

By comparing the sand production profiles of two vertical wells under Cyclic Steam Stimulation (CSS) completed in the same zone, it was found that the use of AMPCP can help reduce sand production significantly over the SRP. This is attributed to the difference in working mechanisms of both pumps. In AMPCP, the fluid is being pumped by a smooth movement, while in SRP, the upstroke and downstroke movement of the pump have an effect similar to the plunger, which adversely impact the sand arch building. As a result, SRP has a higher tendency to produce more sand compared to that of AMPCP.
Experiments and Simulations of Local Upstream Gas Accumulation Giving Unstable Production in a Flowline/Riser System
Authors: Kjeldby Tor Kindsbekken , Nydal Ole Jørgen
Published: December 2014

A set of small-scale air/water experiments has been carried out in a flowline/riser system to demonstrate how local gas accumulation in regions upstream from a riser or a well may give unstable flow, with cycling liquid production at the riser outlet. This unstable flow phenomenon differs from the well-known severe-slugging instability phenomenon in that the instability is driven by gas expansion in the riser, and not by expansion in the upstream pipeline.

A Lagrangian slug tracking model was extended with the option of solving problems with entrained gas in slugs, and used to simulate the experiments. A simplified pressure/momentum scheme is applied. Sensitivity analyses were carried out for selected parameters. Good correspondence between experiments and simulations was found with respect to the period of the instability cycle for this gravity-dominated system. The experimental stability limits are also well reproduced.
Integrated Predrill Pore-Pressure and Borehole-Stability Prediction for Prelude Development
Authors: Hansen K.S.. S. , Wang G.. , Adeleye O.. , McNeil K.V.. V. , Couzens-Schultz B.A.. A. , Azbel K.. , Sarfare M.. , Tare U..
Published: December 2014

Pore-pressure (PP) and fracture-gradient (FG) predictions were prepared for Prelude development wells in the Browse basin in offshore northwest Australia. The PP forecasts were based on resistivity- and sonic-based models calibrated with pressure measurements and drilling events, such as kicks from existing wells. FGs were based on leakoff tests and loss events from offset wells and were not necessarily equal to either the minimum compressive principal stress (often considered a lower bound to FG) or the formation-breakdown pressure (often considered an upper bound to FG that includes effects of formation tensile strength and near-wellbore hoop stress). The minimum compressive horizontal stress was calculated from lithology-dependent effective-stress ratios. Maximum horizontal stress was inferred from observed breakouts. PP and stresses were combined with formation properties from well logs and laboratory rock-mechanics tests to provide input for elastoplastic (shales) and poroelastic (sands) borehole-stability (BHS) models.

These techniques are applicable to exploration, appraisal, or early-development wells that have potential for encountering geopressured formations in high-angle well sections requiring good predrill estimates to adequately plan the casing and drilling programs and determine BHS. The predrill studies can be extended to provide integrated real-time PP and BHS while drilling, and the models can be recalibrated after each well to provide updated predictions for subsequent wells.

There are only minor deviations in the predicted PP and FG among the different well locations considered. Common features include potential loss zones in the shallow overburden, pressure ramp within the Jamieson, pressure regression below the Aptian, and near-hydrostatic pressure within the Upper Swan and below. The BHS models indicate that minimum-required mud weight in deviated sections could be up to 20% higher than that required to balance formation PP. In one well that would cross a suspected fault, the risk of fault reopening or reactivation is low.
Laboratory-Scale-Model Testing of Well Stimulation by Use of Mechanical-Impulse Hydraulic Fracturing
Authors: Frash Luke P. , Gutierrez Marte , Hampton Jesse
Published: December 2014

Reservoir stimulation is commonly used to increase well-production rates and enable economic oil and gas recovery from conventional and unconventional reservoirs. One potential stimulation method that has been laboratory tested as a means to increase well injectivity after conventional hydraulic fracturing is mechanical-impulse hydraulic fracturing (MIHF). MIHF is a high-strain-rate stimulation method that uses a mechanical-energy source as an alternative to rapid gas expansion. Field-scale viability of MIHF was evaluated by use of elastic mechanics and thermodynamics. Results from laboratory tests are presented in which associated flow data indicated significant increases to well injectivity after MIHF stimulation. Tests were performed in two granite specimens with dimensions of 300×300×240 mm3 and 300×300×300 mm3, respectively. The first specimen was unconfined at room-temperature conditions, whereas the second was subjected to heating and true-triaxial confinement. Stimulated well injectivity was evaluated with a series of step-constant-pressure and step-constant-flow injection tests.
Assessing the Biotreatability of Produced Water From a Qatari Gas Field
Authors: Janson Arnold , Santos Ana , Katebah Mary , Hussain Altaf , Minier-Matar Joel , Judd Simon , Adham Samer
Published: December 2014

Reuse of significant quantities of produced water (PW) extracted during gasfield operations requires treatment to remove both organic and inorganic materials. Biological treatment is generally regarded as the most cost-effective method for organics removal. For industrial waste waters, biotreatment faces distinct challenges because the PW composition can dramatically affect sludge settleability, a critical parameter in the operation of conventional biotreatment systems. Membrane bioreactors (MBRs) have an inherent advantage and have proved to be successful in the treatment of industrial waste waters because a membrane filter is used to separate the treated water from the sludge rather than separation being contingent on biomass settleability.

The outcomes of a bench-scale experimental study on the application of an MBR to the biotreatment of PW from Qatari gas fields are presented for three operating parameters: hydraulic-retention time of 16 to 32 hours, solids-residence time of 60 to 120 days, and temperature of 22 to 38°C. The impact on chemical-oxygen-demand (COD) removal was evaluated through experimental testing by use of three parallel bench-scale MBRs. Low sludge concentrations (0.3–1.5 g/L of volatile suspended solids) were attained throughout, with instantaneous-flux values ranging from 3 to 15 L/(m2·h).

Results indicated that the COD removal averaged 60% (54–63%), approximately one-third of this value being attributed to physical removal, with the operating parameter values shown to have no statistically significant effect on removal. Although trends were consistent with some previously reported studies performed on refinery waste water, overall removals were lower than expected. The pH of the bioreactor sludge ranged from 4.9 to 6.0, averaging 5.2, compared with a feedwater pH of 4.3, possibly contributing to the low carbon removal recorded. Adjustment of the feed pH to more than 6.5 caused a precipitate to form that contributed to membrane fouling. However, all feedwater acetate and more than 90% of the oil and grease were removed by the MBR treatment.

Treatment appeared to be carbon-limited, accounting both for the absence of nitrification (with all removed organic nitrogen apparently being assimilated into the sludge) and for the low sludge-solids concentrations attained. Evidence suggests the feedwater contains a significant fraction (approximately 40%) of highly recalcitrant organic compounds presumed to be nitrogen-containing field chemicals (e.g., scale inhibitors and corrosion inhibitors).
Experimental Study on Sand-Carrying Mechanism and Capacity Evaluation in Water-Producing Gas Wells and its Application in Artificial Lift Optimization
Authors: Dong Changyin , Li Yanlong , Zhang Qinghua , Feng Shengli , Zhang Lihui
Published: December 2014

For the unconsolidated gas reservoir with sand production, when the gas well produces water, the flow in wellbore is essentially gas-liquid-solid three-phase flow. The flow mechanism and sand-carrying capacity tend to obviously affect the artificial lift system operational situation and optimization. In this paper, the gas-liquid-solid multi-phase flow with different water-gas ratio (WGR) and sand concentration were experimentally simulated to investigate the flow mechanism and sand-carrying capacity of gas-liquid flow. The results indicate that once the well starts to produce water, it's more difficult for the gas to carry produced sand than there is no water produced. Gas flow rate and WGR are the dominant factors affecting the flow mechanism. As WGR increasing from zero, the flow pattern tend to be mud-gas flow with no sand carried, annular flow with sand, plug flow with sand and further patters similar to these of normal gas-liquid two phase flow with the same WGR. The prerequisite of sand-carrying can be described as that the gas be able to carry liquid flow to a certain velocity, at which the liquid has enough velocity to carry the sand flowing contained. According to the systematic experimental results, the critical sand-carrying gas rate and the quantitative relationship of sand rate and gas flow rate were obtained. Based on the experimental data, a sand-carrying evaluation model for gas well with and without water production are developed. The model is used to predict the critical sand-carrying gas flow rate with certain sand diameters and the maximum sand rate carried by a given gas flow rate. Finally, considering the characteristics of sand-carrying in wellbore, a new integrated coordination chart for gas well with water and sand production is put forward to evaluate the real well operational situation and help to make decision of well measurement such as adjusting gas nozzle, sand control and others. The method has been applied in Sebei gas filed, a typical gas filed with serve sand and water production, and the effect is good.
Real institution: Document and realism
Authors: Bojanic Petar
Published: December 2014

Regardless of the fact that I am using certain texts by Searle, Ferraris,
Smith and De Soto, my intention is not at all to reiterate someone else?s
position in my own words, nor is it to question or modify some such position.
My intention for now is to, using Ferraris? theory of the document, affirm
the existence of a paradox - one rejected by Searle, but unconvincingly so, I
think - regarding the institution (or the institutionalization of the
institution). In order to do that, it seems to me that I am forced to
slightly disturb both Searle?s and Ferraris? conception, in attempting to
offer my own contribution to a new future theory of the institution.
The French state and the church: Socio-historical context, structural conditionality and character of laicism
Authors: Mladenovic Ivica
Published: December 2014

In the article, the author deals with the political and social influences of
the relationship between the state and religious communities in France. The
first part of the paper is an analysis of historical context and the
construction (evolution) of laicism in France through its local
characteristics, values and social strengths, contributing to its formation.
The fact that Catholic Church was one of the main legitimizing pillars of
?the old regime?, permanently determined the relationship between church and
state, most importantly - it?s subsequent social exclusion under the
Republic. The 1789 French revolution in conjunction with the 1905 law on the
Separation of church and state, up until present time, have been seen as the
most important events in defining the relationship between political and
religious entities in France. The second part of the paper continues in
outlining the founding logic and principles of the contemporary relationship
between religious communities and the French state. The article concludes in
suggesting that through its persistence of a purely Laicistic model of
state-church affiliation, view of the nation as a community of citizens,
Weberian definition of the State, and the acceptance of the public sphere as
common space in which communal interests are negated, France today represents
an isolated island on the European continent.
A left „theocracy“: The church and the state in revolutionary Nicaragua
Authors: Jakopovich Daniel
Published: December 2014

This paper analyses the antagonism between the established (Nicaraguan and
global) Catholic Church and the Sandinista movement and government, which was
one of the focal points for the ascendancy of a continental and global
liberation theology movement. The paper provides a critical overview of the
Nicaraguan liberation theology movement, as well as Sandinista strategies,
primarily in relation to the social functions of religion and religious
institutions. The central focus of this essay is to identify how the
left-theological and Sandinista understanding of the imperatives of the
counter-hegemonic project, the ?historical bloc? (conceived as a system of
political and social networks and alliances) and the ?national-popular?
strategy contributed to the tentative naissance of a novel state religion and
a novel political project: a left-wing ?theocratic? social order. The
Nicaraguan experience is useful for focusing the wider discussion about the
importance of context-specific normative judgments about Church-state
relations.
The intentionality of madness: Checking the cognitive issues in DSM-based diagnosis
Authors: Fatic Aleksandar
Published: December 2014

In this paper I discuss John Searle?s selective view of intentionality of
mental states, and place it in the context of impairment to personal identity
that occurs in mental illness. I criticize Searle?s view that intentionality
characterizes some but not all mental states; I do so both on principled and
on empirical grounds. I then proceed to examine the narrative theory of self,
advanced by Paul Ricoeur, Marya Schechtman and others, and explore the extent
to which the theory fits a more generalized view of intentionality that would
apply to all mental states. This discussion is followed by a brief
consideration of the way in which the modern DSM-based psychiatric diagnosis
and treatment, reductively and mechanistically, dispenses with the issues of
?strong ontology?, namely the life events and values that mental states might
in fact reach for, even when ostensibly without reference. In this sense,
DSM-inspired psychiatry is based on a Searlian view of mental states. It is
contrasted with the narrative theory of self (and therefore also of mental
states) which, rather than defining madness by clusters of symptoms, seeks to
understand the underlying ontology of reference by looking for both the
initial script of the person?s ?life narrative? and for ruptures and knots in
that narrative that might give rise to madness. Finally I discuss and
evaluate the perspective of personality enhancement through counseling aimed
at repairing the personal narrative.
The problem of reality in writings of Richard Wagner reality of artwork as transition from „reality of the contemporary world“ towards „reality of the future world“
Authors: Jeremic-Molnar Dragana
Published: December 2014

Richard Wagner began perceiving the world in terms of decay as early as the
mid-1840s and especially during the 1848-49 revolution. He did not critique
the contemporary world (and its accompanying reality) as someone who merely
understood it in his own way. Wagner actually developed his own version of
the world that was meant to become the referential framework for creating an
entirely different reality in the future. The most exhaustive source
concerning Wagner?s idea of the world and reality is his famous letter to
August R?ckel, from 25-26 January 1854. In it Wagner put together his earlier
ref lections on reality into a relatively coherent and meaningful whole. He
did it by the means of several different concepts: ?the World as a whole?,
?the actual world?, ?reality of the world?/?the modern reality?. In this
letter and elsewhere, he failed to elaborate his idea of the world, as well
as to explain its relationship with ?the modern reality? that was undergoing
change. Instead, he developed another idea: that of the artwork which was
supposed to be a sort of mediator between ?the actual world? and ?the world
of the future?, as well as between their accompanying realities. Wagner?s
version of the ?actual world? (as well as its appropriate reality) comprised
two components: ?the actual world? itself and the artwork, which was already
changing it. Such a work contained a description of the change, understood in
terms of regeneration, and thus also a prediction of the way reality itself
should change in the future, as well as the direction of the change.
CaSO4 and cationic polyelectrolyte as possible pectin precipitants in sugar beet juice clarification
Authors: Kuljanin Tatjana , Loncar Biljana , Pezo Lato , Nicetin Milica , Knezevic Violeta , Jevtic-Mucibabic Rada
Published: December 2014

Three pectin preparations were isolated from fresh sugar beet pulp during the
150 minutes of extraction, at pH values of 1, 3.5 and 8.5. CaSO4 precipitant
was added to 100 cm3 of 0.1% (wt) solution of pectin. Studies were performed
with 9 different concentrations of CaSO4 solution (50-450 mg dm-3) with the
addition of a cationic polyelectrolyte (cationic PAM) in concentrations of 3
and 5 mg dm-3. The efficiency of pectin precipitation was monitored by
measuring the zeta potential of pectin preparations. Optimal amounts of
precipitant CaSO4, without the use of a cationic polyelectrolyte, were as
follows: 490-678 mg CaSO4/g pectin. After the use of a cationic
polyelectrolyte, the optimal amounts of CaSO4 were smaller (353-512 mg/g
pectin). These quantities are significantly lower than the average amount of
CaO used in the conventional clarification process of sugar beet juice (about
9 g/g pectin of sugar beet juice).
Crowding-out or crowding-in? Analyzing the effects of government spending on private investment in Turkey
Authors: Şen Hüseyin , Kaya Ayşe
Published: December 2014

The main objective of this paper is to analyze empirically the effects of
government spending on private investment, evaluating the existence of
crowding-out/-in effects, in Turkey for the 1975-2011 period. In contrast to
previous studies, we employed in the paper the modified version of David A.
Aschauer?s (1989) model, which allows us to see the effects of each component
of government spending taking place in the Turkish budget system. The
empirical findings of the paper showed that government current transfer
spending, government current spending, and government interest spending
crowdout private investment, whereas government capital spending crowds-in
private investment in Turkey.
Contradicting the twin deficits hypothesis: The role of tax revenues composition
Authors: Obadic Alka , Globan Tomislav , Nadoveza Ozana
Published: December 2014

The general theory of twin deficits hypothesis does not consider specific
characteristics of domestic tax systems, i.e. whether the revenue side of the
budget is dominated by indirect or by direct taxes. The main hypothesis of
the paper is that in countries with fiscal systems dominated by indirect
taxes, the deterioration of the current account balance would imply higher
fiscal revenues due to larger imports and consumption. The hypothesis is
based on the characteristics of domestic tax systems of Bulgaria, Croatia,
Poland and Romania in which indirect tax revenues account for the majority of
total budget tax revenues. Results suggest that the co-movements of the
current account and the fiscal balance cannot be explained by the twin
deficit theory in countries with indirect tax-oriented systems. These results
imply that only the structural economic transformation and export orientation
of the economy may reverse the causality direction between two deficits.