bluuebunny/crossref_metadata_2025_split huggingface dataset:
Application of Analytical Technique for Streamline and Flood-front Mapping in Giant Offshore Carbonate Reservoir
Authors: Nautiyal D. K. , Jain P. K. , Lohar B. L. , Marathe R. V. 
Published: March 2012

Abstract
A giant multi-layered carbonate reservoir in offshore India is undergoing water-flooding since 1987. Historically there have been about 930 producer and 250 injection strings in the field with about half of them active today. In order to have quick flood surveillance, flow streamline snapshots and flood-front maps have been attempted using in-house developed analytical technique assuming homogeneous, incompressible, unit mobility ratio displacement process.
The eleven producing unit of the reservoir are clubbed as five major stacks for streamline generation. Injection and production volumes are divided among these five stacks on the basis of existing history matched simulation model. The volumes are then normalized to obtain the relative strengths of the producers and injectors Macro level reservoir anisotropy is inherently taken care by the normalization process of rates. Reservoir boundary for each stack is simulated by placing large number of image wells along each boundary. The velocity and potential distribution in the reservoir are obtained using the principle of superposition. The velocity equation tracks the path of the fluid particle generating the flow streamlines.
Flood-front positions are generated by repeating the above process. The field water cut vs. pore volume of water injected is compared against the actual water cut vs. pore volume of water injected as a history matching process. Individual well water-cut are then superposed on the flood-front positions in the corresponding stack.
Flood front positions are corroborated to a large extent with the superposed water-cut in individual wells. Deviations in the actual water-cut trend are also observed in few areas. Recommendations for redistribution of injected water among the identified stacks are presented on a holistic basis to achieve better sweep efficiency in the reservoir and field trials are awaited.
The attempt is to use this fast and simple analytical technique on a desktop computer for quick water-flood surveillance of a large field.
Optimising Exploitation Strategy of Multi layered Reservoir for higher recovery – A Case Study of an Aging Field, Cambay Basin, India
Authors: Dubey Prashant K , Mishra Pranav K , Walia Ashok , Lohiya J. P. 
Published: March 2012

Abstract
The HC field was discovered in 1972 and put on commercial production in 1974. The field’s oil production reached life-time high of 461 tpd (tonnes per day) in June, 2006. However, soon the production started declining, rather rapidly, and average production during 2009-2010 was mere 220 tpd, which necessitated an integrated review of the field, combining geosciences, reservoir engineering and production technology. Study started with organizing abundant and scattered field data, recording of Cased Hole Formation Resistivity (CHFR) / Reservoir Monitoring Tool (RMT) and Cased Hole Compensated Neutron (C/H CNL) logs in key wells, which tagged shifted fluid contacts and modified saturations. Past performance of the sands was studied and reservoir simulation carried out for obtaining suitable perforation policy for sands with GOC and OWC. Shale/coal barriers were identified and their reliability was tested for two reservoir units, which helped in putting the rim of oil between GOC and OWC on production. Based on the integrated study, opportunities were identified and well interventions through work-over jobs were carried out for recompletion, zone transfer and water shut-off. Geology of the main block was redefined integrating seismic and new data gathered from four strategically newly drilled wells.
Further, a strategy was firmed up for rational exploitation of all sands in the multi-layered block aiming at maximising recovery and minimizing development and operating cost. Implementation of the study augmented field’s production to a second plateau with increase in production from 220 tpd to 375 tpd.
Simulation of In-Situ Combustion Process in Balol Pilot
Authors: Dayal H. S. , Bhushan B. V. , Mitra Sujit , Pandey Vivek , Bhandari A. C. , Dwivedi M. M. 
Published: March 2012

Abstract
The In-situ Combustion (ISC) process has been successfully applied in the Southern part of Balol field for the last 21 years. This sector has oil of 300 cp viscosity and 15° API. The Pilot was initiated in 1990 followed by semi-commercialization in 1992 and commercialization in 1997. It has been instrumental in enhancing the oil recovery from 13% to 50%. The ISC process in the pilot stage has been modeled on the thermal simulator. At first, the 1-D Combustion tube experiment has been successfully modeled and history matched with single equation incorporating the oxidation of heavy oil. The reaction kinetics from Combustion tube model with suitable modification and the Equilibrium Constants obtained from the Equation of State (EOS) modeling of PVT experiments has been utilised to history match the ISC pilot performance.
The ISC model calibrated from the history match of the actual data of the pilot shall enable in simulating the ISC process in the semi-commercial and the commercial phase. It would help in optimization of air injection rates, placement of air injectors, propagation of the combustion front, performance prediction and finally the ultimate recovery.
The successful history match of the ISC process in the Pilot area in terms of water cut, liquid rates has enabled better understanding of the process. It was possible to obtain a good agreement for the propagation of the combustion front and the temperature distribution.
The study has indicated that the ISC simulation on thermal simulator using single equation can be used as significant stepping stone in modeling the process in more detail using multiple equations and incorporating larger area.
Unlocking Potential of Offshore Marginal Fields in India: A Success Story
Authors: Nischal Rajiv , Kumar Adesh , Vasudeva Sudhir 
Published: March 2012

Abstract
Marginal field refers to a field which due to various factors (geologic, geographic, technological or economic) may not produce enough net income to make it worth developing at a given time. However; should technical or economic conditions change, such a field may become commercially viable. It is usually associated with small pockets of hydrocarbons that have a plateau of a few years.
Currently, ONGC has more than 165 such small and marginal fields totaling reserves of more 297 MMT. Most of these are far away from existing infrastructures, located at great water depths or contain insufficient reserves distributed in multiple pays to consider development on a stand-alone basis. Concerted efforts involving complex combination and integration of human resources, advanced technologies improving scale of economies by integrated cluster development and changed economic scenario, many of these fields could be made economically feasible. This led to monetization of 53 fields till date and 69 fields are under various stages of monetization.
The paper illustrates through case histories the approach followed for the integrated development of these marginal fields in offshore, with special emphasis on: - grouping of marginal fields with economic fields, cluster development, modularization and standardization of process facilities/wells for optimizing cost, revamping existing jack-ups as mobile processing, CAPEX reduction through hired FPSO and use of advanced techniques like multilaterals, dual completions, zones transfers etc.
Due to these initiatives, oil production for ONGC’s offshore marginal fields is expected to peak at about 1,25,000 bopd and gas production will peak at about 17 MMm3/d in 2014-15.
Case Study: Asia Pacific First Ever Closing of a Fluid-loss Isolation Valve Using Electric Line in a Highly Deviated Well
Authors: Dzul-Fikar Muhamad Nasri 
Published: March 2012

Abstract
An offshore operator in Malaysia detected an unexplained annulus pressure increase after completing a large-bore gas production well. A leak detection tool was run on an electric line tractor and located leaking tubing connections at 333 m and 394 m MD. This led the operator to recomplete the well.
The operator chose to close a fluid loss isolation valve at 1800 m MD. Because an electric line tractor, hydraulic stroking tool, and key tool were already onboard the platform as a contingency to open the valve, this suit of technology was chosen to close the valve.
The toolstring was configured with a 4.625" key pad to fit into the sliding sleeve of the valve and run in the hole. The tractor was activated 146 m above the valve and then driven down to the valve where a depth correlation was made. Then the toolstring was placed with the key extended until it reached the recess area above the shifting profile. The piston of the hydraulic stroker was extended with the key pads expanded and located the shifting profile. Next, the hydraulic stroker was activated to stroke up and thereby closed the ball valve.
The valve was closed in 15 hours from rig up to rig down, including 2 hours of inflow test. This was the first time such a valve has been closed on electric line in Asia Pacific and the operation proved the viability and efficiency of the technology. Importantly, the operator did not kill the well and saved significant costs by cutting the time in half compared to a workover.
This paper will present the learning from the operation while discussing this newly adopted approach and the benefits it offers to the industry.
Combination of Dual String Single Trip Multi-Zone Completion Systems and High Rate Formation Pack as a Proven Completion Methodology for an Unconsolidated Reservoir: Case Study Tunu Field
Authors: Laidlaw D. , Agee D. , Madyanova M. , Hustache H. 
Published: March 2012

Abstract
Failures due to sand production can manifest themselves in many ways; from surface equipment damage to downhole equipment failures which can ultimately result in loss of well integrity and worst case catastrophic failure. Several methods are available in the industry to control sand production problems, gravel packing being a widely used method. Gravel packing entails placing a sand or proppant filter in the annular space between an unconsolidated formation and a centralized slotted liner or wire-wrapped screen. Increased mechanical skin and achieving time and cost efficiencies are amongst the many challenges faced when implementing gravel packs as part of a completion operation.
The Tunu field is a large gas field located in the Mahakam delta, East Kalimantan, Indonesia. Gas production started in 1990 and to date hundreds of wells have been drilled in the field. Until recently, the primary target was the Tunu Main formation which is a deep, well consolidated reservoir. To maintain production goals the operator has started to produce from the shallower unconsolidated zones. The first well targeting the Tunu Shallow reservoir was drilled in 2008. The Tunu Shallow formation has average porosity of 28% and permeability of approximately 1 Darcy. Shale content can be as high as 25%. Coal seams are also frequently found interbedded amongst the shales and reservoir sands. Within the interval of 500 to 2,000 m TVD the reservoir is generally found to be completely unconsolidated.
In the Tunu Shallow development, more than 100 zones in 30 wells have been completed using a dual string single trip multi zone gravel pack completion system (STMZ) in combination with high rate formation packing (HRFP) as the sand control method. Using these combined techniques has given excellent results in terms of well productivity, rig non-productive time (NPT) and costs. Analysis performed on data garnered from pressure build-up tests (PBU’s) show mechanical skins ranging from 10 to 21 with an average of 14 obtained. The wells produce up to 24 MMscf/D sand free. This paper explains the implementation and optimization of the STMZ completion system with HRFP treatments as a completion technique in the shallow sands of the Tunu field.
Failure Analysis of An Onshore Pipeline in Petroleum Industry – A Case Study
Authors: Talukdar Maushumi Kakoti , Kujur Abhay , Bhat S. , Sahota S. K. 
Published: March 2012

Abstract
The premature failure of an onshore underground well fluid line led to a fatal fire incident. Though there is no reduction in overall thickness localized internal corrosion were noticed at both 6 O’ clock and 12 O’ clock position. In some localized area near the weld there is heavy metal loss leading to formation of holes at 6 O’ clock position
Results of various laboratory investigations confirm that the corrosion and premature failure of pipeline sample was caused by localised corrosion attack. The calculation of flow regime confirms that the flow is stratified and software analysis shows that deposition of water is throughout the whole length of the pipeline thereby creating an ideal condition for deposition and growth of bacteria colony. Two different corrosion mechanisms namely microbial induced corrosion and localized corrosion of chloride have acted together and resulted in the severe attack at 6 O’ clock position. With MIC being the most pronounced. The condensed water and acid gases have caused localized corrosion often called top line corrosion at 12 O’ clock position. Therefore the flow condition, presence of high concentration of chloride and bacterial activity has acted in synergy to cause this failure of the pipeline.
Offshore Drilling & Well Testing Of A HPHT Gas Well: A Case Study
Authors: Shah Prerak H , Pandya Harsh T , Sharma Harsh , Saxena Arpit 
Published: March 2012

Abstract
With exploration in harsh environments and consequent high pressure and temperature conditions, the calculation of reservoir properties has become complex and thus the changes in pressure transient response need to be understood and appreciated by taking appropriate challenging measures.
The paper deals with the various challenges arising when dealing with the drilling and testing of HPHT gas wells with Hydrogen sulfide and Carbon dioxide, located in Krishna Godavari (KG) Basin and the difficulties faced while executing it. The paper focuses on the experience while drilling the reservoir with a different mud program and mechanical failure caused by HPHT conditions & highly corrosive environment. The paper also highlights the preference of SOBM over WBM while drilling the reservoir section. It also describes the learning process as the exploratory well campaign progresses from one well to other. It briefs about the challenges while performing MDT as per the program in these high temperature environment. The paper briefs about the decision involved in selection of proper grade tubing, elastomer, packer, flowhead equipments, DST tools & explosives in this HPHT environment along with Hydrogen sulfide & Carbon Dioxide. In any gas well testing, exhaustive amount of data over the requisite period of time are necessary; data redundancy necessitates redressing of equipments. The biggest challenges faced by industry are high temperature rather than high pressures, so making metallurgy an important basis of consideration. It also highlights about the method followed during correlation of prospective zones using different logs.
The paper discusses the unexpected results and observations obtained during execution of our program and the lessons learnt from it.
How Real-Time Surveillance Improves the ESP Run Life, Uptime and Reduces Production Deferment
Authors: Abdel-Basset Mohamed , Elbarkatawy Aied , Elsherif Mamdouh , Eraky Hesham , Matar Hossam , Hashim Sameh 
Published: March 2012

Abstract
This paper explains how the real-time surveillance helps improving runlife, uptime and reducing production deferment of Electrical Submergible Pumps (ESP) of SG-300 offshore platform wells of Gulf of Suez Petroleum Company (GUPCO). The implementation of a robust suerveillance workflow together with real-time surveillance and alarm notification system has shown a good contribution to increase ESP runlife via preventing the ESP from being misoperated outside its recommended operating conditions and experiencing excessive stress, reduce start/stops and downtime, reduce production deferment, and improve downhole chemical injection program for scale inhibition. This is being done via classification of alarms and on-fly diagnostics of main root causes that helps to promptly identify remedial actions and/or recommendations.
Resolving a Permeabilty Mismatch in a Mature Carbonate Field
Authors: Oates Michael , Mishra Gaurav , Sultana Nazneen , Nath Gitashree 
Published: March 2012

Abstract
A close scrutiny of core data from a producing carbonate field resolved an apparent difference between permeability evident from core plug analysis and from testing of wells in the field. This was attributed to a bias inherent in the data collection, particularly as the samping techniques avoided the most permeable features. Instead of invoking a pervasive fracture network in the static geological model, which might compromise a planned water injection campaign, it is now evident that the permeability mismatch can be satisfactorily modeled with a horizontal multiplier, and that water injection should result in a significant increase in ultimate oil recovery.
Entrepreneurial Attitudes in a Post-Communist Transitional Rural Economy: The Case of Moldova
Authors: O'Brien David , Españo Eloi , Grigsby Mary , Patsiorkovsky Valery 
Published: March 2012

Entrepreneurial Attitudes in a Post-Communist Transitional Rural Economy: The Case of Moldova
A sample survey of small and medium-sized farms in Moldova is used to examine the prevalence of different aspects of an "entrepreneurial outlook" in a post-communist transitional economy. Within the range of less than 1 to 100 hectare farms, the most pronounced differences are that operators of larger farms have greater "technical knowledge" of different aspects of high value agricultural production and sales as well as having a greater willingness to deal with "uncertainty and debt."
Contributions to the Knowledge on Staphylinids (Coleoptera: Staphylinidae) in Some Riparian Ecosystems of South-Eastern Romania
Authors: Stan Melania 
Published: March 2012

Contributions to the Knowledge on Staphylinids (Coleoptera: Staphylinidae) in Some Riparian Ecosystems of South-Eastern Romania
The diversity of the staphylinid fauna is investigated in some riparian ecosystems along rivers of south-east Romania: the Danube, Prut, Siret, Buzău. 94 staphylinid species and subspecies were identified from 23 investigated sites. Thecturota marchii (Dodero) is a new record for the Romanian fauna. Leptobium dimidiatum (Grideli), a rare species, is recorded from a new site, the second record from Romania.
Automatic segmentation of separately pronounced Sinhala words into syllables
Authors: Priyadarshani P. G. N. , Dias N. G. J. 
Published: March 2012

Aligned corpora are widely used in various speech applications like automatic speech recognition, speech synthesis, as well as prosodic and phonetic research. The segmentation into syllables can be done manually or automatically. But it consumes significantly more time for a fully manual phonetic segmentation and practically it is a complicated task because in many cases it requires a large aligned speech corpus. If the manual syllabification is done by a group of individuals then the consistency is decreased because the analysis variations of the individuals. Consequently, there is a dire need for automatic syllabification and it is important because Sinhala language is syllable centric in nature. A method for syllabification of acoustic signals of separately pronounced Sinhala words has been given. Detecting the syllable boundaries was achieved by two main phases and those phases have been described with examples. Keywords: syllabification; oscillograph; vowel; consonant; envelope; thresholdDOI: http://dx.doi.org/10.4038/josuk.v6i0.4219 J Sci.Univ.Kelaniya 6 (2011) : 35-44
CD80 Expression on B Cells Regulates Murine T Follicular Helper Development, Germinal Center B Cell Survival, and Plasma Cell Generation
Authors: Good-Jacobson Kim L. , Song Eunice , Anderson Shannon , Sharpe Arlene H. , Shlomchik Mark J. 
Published: March 2012

Abstract
Germinal center (GC) B cells and T follicular helper (TFH) cells interact in the production of high-affinity long-lived plasma cells (PCs) and memory B cells, although the mechanisms regulating the formation of these long-lived populations remain unclear. Because CD80 is one of the few markers shared by human and murine memory B cells, we investigated its role in the development of GCs, memory cells, and PCs. In CD80-deficient mice, fewer long-lived PCs were generated upon immunization compared with that in B6 controls. In concert, the absence of CD80 resulted in an increase in apoptotic GC B cells during the contraction phase of the GC. CD80−/− mice had fewer TFH cells compared with that of B6, and residual TFH cells failed to mature, with decreased ICOS and PD-1 expression and decreased synthesis of IL-21 mRNA. Mixed bone marrow chimeras demonstrated a B cell-intrinsic requirement for CD80 expression for normal TFH cell and PC development. Therefore, B cell expression of CD80 plays a critical role in regulating B–T interactions in both early and late GC responses. This, in turn, results in impaired ability to produce long-lived PCs. These data provide new insights into the development of GCs and Ab-forming cells and the functions of CD80 in humoral immunity.
Vertebral Bone Mineral Measures and Psychological Wellbeing among Individuals with Modic Changes
Authors: Briggs Andrew M. , O'Sullivan Peter B. , Foulner Deryck , Wark John D. 
Published: March 2012

Purpose This case-control pilot study examined whether vertebral bone mineral measures were associated with the presence of chronic low back pain (CLBP) and Modic changes (MCs), and to compare psychological wellbeing and inflammation among individuals with CLBP and MCs, compared to individuals with no history of low back pain and without MCs. Methods Eleven individuals with MRI-defined MCs in the lumbar spine and CLBP (cases) and 10 individuals with no history of CLBP or MCs (controls) responded to standard questionnaires regarding pain characteristics and psychological health. Bone mineral density (BMD) was measured with postero-anterior and lateral-projection dual energy X-ray absorptiometry (DXA) to estimate areal BMD (aBMD) and apparent volumetric BMD (ap.vBMD). High sensitivity serum C-reactive protein (hsCRP) was measured as an index of inflammation. Results While there was no difference between the groups in measures of depression, anxiety and stress, cases reported significantly greater pain catastrophizing attitudes ( P < 0.01). hsCRP concentrations did not differ between groups ( P = 0.54). Among the 7 cases where MCs were identified between L3–4, significantly higher mean aBMD was observed at the affected vertebral level, compared to the adjacent, unaffected, cephalad level ( P = 0.01–0.04), but not when ap.vBMD was calculated ( P = 0.36). Conclusions Vertebral BMD is not reduced among individuals with CLBP and MCs compared to a control group, although pain catastrophizing attitudes are increased among individuals with CLBP and MCs.