bluuebunny/crossref_metadata_2025_split huggingface dataset:
Case Study of the Impact of Cold and Hot Waterflooding Performance by Simulation and Experiment of High Pour Point Oil Reservoir, Liaohe Oilfield, North-east China
Authors: Zhou Wei , Tang Zhong-hua , Orodu Oyinkepreye D. 
Published: January 2010

Abstract
Block Shen-95 has been under cold waterflooding for 17 years. Of particular interest is the low recovery of 11.27% for the North Block due to crude oil cloud point being very close to the reservoir temperature. Formation damage near the wellbore region is controlled at production wells by hot-oiling and low injection rates of non-isothermal waterflooding.
Optimizing production necessitated looking at core-scale experiment and reservoir-scale simulation waterflooding performance at different temperatures. The intent also, is basically to condition core-scale flooding observations to properly initialize the numerical model. Based on experiment carried out on core samples, sharp decline in oil displacement efficiency occurred, increase in residual oil saturation and increase in the intensity of formation damage below the cloud point. Reservoir simulation depicted decline in production with decreasing flooding temperature captured specifically by change in viscosity around the wellbore region. Change in flow dynamics due to change in relative permeability was not efficiently captured and formation damage impact on porosity and permeability.
Reservoir-scale performance for high pour point oil reservoir can better be understood by considering the effects of formation damage on storativity and transmissibility, and fluid rheology. The irreversible process of wax precipitation may cause permanent damage if further from the wellbore region.
Single String Packerless ESP Gas Lift Hybrid; Optimizing Production and Minimizing Loss
Authors: Prakoso N. F. 
Published: January 2010

Abstract
Kaji Semoga (KS) field has produced primarily from limestone and has until recently contained sufficient gas for gas lift usage. However, KS gas production is declining rapidly: it is estimated that by 2013 it will produce insufficient gas. As a result, some new forms of artificial lift are being considered to replace gas lift, and since the end of 2008 new ESP and HPU projects have been carried out with the aim of such a new form of lift. As a result of implementing these projects, ESP wells will be the dominant artificial lift for production wells in KS, contributing to approximately 70% of total oil production
On the other hand, there are risks of downtime associated with the use of ESP. The main risks concern downhole problems, which need rig deployment, and electrical problems, which cause the ESPs to shut down. Fixng these problems may require a considerable amount of time - several days or even weeks - due to reasons such as unavailability of a rig and/or spare parts. This will inevitably result in loss of oil .production.
To avoid such production loss, an ESP / gas lift hybrid system has been implemented, whereby gas lift is prepared as a backup. This hybrid system consists of an ESP unit installed along with a gas lift system in single tubing, with no packer and 1 (one) (screen orifice) gas lift valve, 1 (one) sliding sleeve door, and 1(one) complete ESP unit.
All ESP wells in KS (currently 70 wells and counting) now use this configuration. The gas lift hybrid system has been used as backup during ESP downtime. This configuration can produce 35% of liquid compared to normal ESP liquid production, and as a result an oil loss of 4400 bbls was prevented during 2009.
Flood Front Estimation With Streamline Modeling: A Case Study of a Mature Field in Assam, India
Authors: Singh A. K. , Jain V. K. , Marathe R. V. 
Published: January 2010

Abstract
Waterflooding as a means of secondary recovery is one of the oldest techniques used in the petroleum industry. The design and development of the waterflood usually attracts the most attention and surveillance is a relatively less rigorously followed practice, although its importance in the waterflood's success cannot be understated. There are many techniques for monitoring a water injection/waterflood project. Estimation of flood front with Streamline modeling is a simple and powerful method to understand the injected water movement as it offers a direct visualization technique to map the flood front. This understanding is also at par/ supplementary to finite difference Simulation in mostof the cases.
This paper describes a field example of estimation of flood front movement in a mature oil field using in-house developed Streamline modeling based on which infill drilling was optimized and fresh areas were identified for new inputs which added economic value to the Asset.
The case study brings out the technique's effectiveness as a simple, low cost, quick look tool of Reservoir Surveillance in waterflooding and how it can be used in such cases.
Based on the results presented herein, it is concluded that such innovative methods for quick decision making including economic aspects can make the difference while selecting surveillance methodology.
An Integrated Approach for Development of KG Offshore Marginal Fields
Authors: Gomathi M. , Kumar Anil 
Published: January 2010

Abstract
A number of discoveries in Tertiary Sequence have been made in shallow water Krishna Godavari offshore along with several new pools. These discoveries are spread over an area of 130 sq.km, lie in water depths ranging from 8 m to 20 metres and are located at a maximum distance of approx.15 km from shore. Some of the discoveries having substantial volumes in this area have already been commercialised and put on production since 2001.
As these discoveries are dispersed in scattered pockets, it is imperative that the development plan considers an economically viable integrated approach. Innovative technical and commercial advances have enabled operators worldwide to develop fields once considered uneconomical or marginal. This paper discusses economisation strategies such as The feasibility and methodology of developing these fields using a cluster based phased approach for early production and better field management.Tie-in strategy to existing and planned offshore and onshore infrastructure in the vicinity.Early production from existing nonexpendable wells either through commingled or sequential production depending upon reservoir characteristics and operational feasibility have been taken into consideration.Drilling of appraisal /development well has been considered only where economic conditions are favourable.The feasibility of developing these fields using minimum facility platforms including leased or new built re-locatable self-installing platforms has been worked out. The design premise of considering this type of platforms is to minimize fixed platform structures, re-use of these platforms for future marginal field discoveries and a more efficient capital expenditure profile.
Digital Oilfied Workflows for Increased automation
Authors: Pande Anil 
Published: January 2010

Abstract
With the ever increasing difficulties related to finding reservoirs, as well as the harsher and more remote environments that they exist in, there is a need to make the best use of workflows and automated processes that leverage digital technologies based on oilfield automation for end to end flows, so as to meet the desired business objectives. This paper discusses the basic requirements to achieve these objectives, by covering what are the essential elements for end to end workflows, based on automation in different stages of the oilfield, that is the basis for technology driven workflow processeses.
Refinement of Chemical Selection for the Planned ASP Pilot in Mangala Field - Additional Phase Behaviour and Coreflood Studies
Authors: Pandey Amitabh 
Published: January 2010

Abstract
Mangala is the largest discovered oil field in the Barmer Basin, India. Initial oil production began in September 2009, and an alkaline-surfactant-polymer (ASP) pilot will start-up early in 2010. Details on the design of the ASP pilot including the laboratory evaluations and simulation studies have been presented earlier. Laboratory evaluations involved screening and optimisation of the ASP slug formulation based on IFT measurements, adsorption measurements, polymer rheological and thermal stability studies, and a series of linear and radial corefloods. Additional experiments were conducted for refinement and optimization of the chemical selection, specifically targeting even lower residual oil saturations than what was attained previously.
These experiments focused on new surfactant types that are more suitable for solubilising the viscous and waxy Mangala oil. The focus was on detailed phase behaviour evaluation rather than physical measurement of IFT, which allowed relatively quick analysis of a number of surfactants in a short time period. Both salinity scans and oil scans were performed because of significant acidic components in the Mangala crude which react very favourably with injected alkali to produce in situ soap. The resulting phase diagram confirmed the presence of a favourable salinity gradient for the ASP flooding. The best chemical formulation was used in long (1ft) Berea and composite Mangala corefloods and showed very high displacement efficiency for relatively low surfactant concentration, which confirmed the robustness of the phase behavior approach for chemical selection. Mechanistic simulations using the UTCHEM simulator assisted in further optimization of the ASP slug formulation. These experiments helped refine the chemical selection for the planned EOR pilot and reduced the technical risks by improving the robustness of the slug design.
Case History: First Isochronal Reservoir Test Successfully Performed Worldwide at a Bottomhole Temperature Greater Than 430° F
Authors: Khati Milind , Pedrosa Luis , Farooqui M. Y. , Khan Z. A. 
Published: January 2010

Abstract
Gujarat State Petroleum Corporation, Ltd (GSPC) wished to evaluate a reservoir in an offshore well on the Indian East Coast where bottomhole temperature was more than 433°F. The Initial DST had shown significant potential for the zone of interest; and therefore, GSPC decided to perform isochronal testing to obtain more detailed reservoir pressure information. In this environment, the DST tools would be required to function continuously in the high-temperature conditions for more than 16 days in order to retrieve the required data without interruption. These conditions would definitely challenge the capabilities of the currently available drill-stem testing (DST) equipment.
This paper describes how DST tools rated to 450°F-bottomhole temperature and 15,000-psi differential-pressure were configured to maintain integrity and successfully evaluate the well. The tools were annulus pressure responsive (APR) that would be operated with pressure applied to the annulus from the surface. The string included a multi-cycle downhole tester valve, a multi-cycle circulating valve, a blowout preventer (BOP) safety valve, a tubing tester valve, a secondary circulating valve, and safety circulating valves. The multi-cycle circulating valve added the flexibility to displace the string with nitrogen for well stimulation, if the well did not flow.
The data describes the careful preparation of the toolstring, the extreme conditions in which the DST tools had to operate to evaluate the well successfully, and how the meticulously prepared toolstring was capable of meeting GSPC’s requirements. The DST tools performed satisfactorily for more than 16 days during the test.
This job set a world record for the service company for a reservoir test performed in these high-temperature conditions and may have set a world record for all testing operations performed by other service companies as well.
Advantages included elimination of coiled tubing, increased safety for this type of operation, and a reduction of rig time compared to other testing jobs.
Reservoir Model History Matching With Particle Swarms
Authors: Mohamed Linah , Christie Mike , Demyanov Vasily 
Published: January 2010

Abstract
History matching optimisation in Bayesian framework is a fairly recent approach to quantify uncertainty in oil industry. Currently some innovative global optimisation approaches such as evolutionary algorithms and swarm intelligence methods have gained popularity for tackling history matching problems.
Particle swarm optimisation (PSO) is a swarm intelligence approach for solving optimisation problems. In this approach particles are moving points in parameter space. The position of a particle is a candidate solution to the optimisation problem. Each particle searches for better positions in parameter space by updating its velocity according to rules originally inspired by behavioural models of the movement of flocks of birds.
Recently the PSO algorithm has shown to be a promising tool for finding acceptable multiple history matched models quickly (Mohamed et al., 2009). However, the algorithm control parameters which balance between exploitation–exploration trade–off are to be studied for history matching problems. In this paper we investigate some basic PSO variants for updating the control parameters using a real–life case study.
It is shown that PSO could be improved by optimising the PSO control parameters. Some variants converge faster to good fitting regions in parameter space leading to a fewer number of reservoir simulation runs though others maintain diversity of the reservoir models better for this reservoir example. This study helps better employing the PSO algorithm for reservoir model history matching and uncertainty quantification.
Geomechanics, ECD Management and RSS to Manage Drilling Challenges in a Mature Field
Authors: Caicedo H. , Pribadi M. A. , Bahuguna S. , Wijnands F. , Setiawan N. B. 
Published: January 2010

Abstract
The Serang Field, offshore East Kalimantan, Indonesia was discovered in 1973. Production started in 1993. Although it is a mature field with 120 wells, drilling still faces challenges in the form of severe lost circulation and stuck pipe events. Side tracks often need to be drilled and drilling budget overruns can be significant. The 2006 drilling campaign of 5 wells saw the loss of several BHAs and needed 4 sidetracks, due to stuck pipe events.
In order to improve the drilling operation and to uncover root causes of the losses and pack-offs, a detailed geomechanical evaluation was conducted. The study began with a comprehensive data audit and drilling event review. All the captured information and log data was then used to create a Mechanical Earth Model (MEM) for wellbore stability planning of future wells.
Key findings of the study were that lost circulation occurred in high permeability zones in shallow carbonates (8-1/2" intermediate hole section) and were not caused by drilling induced fractures. A contingency plan was developed to drill to section TD with sea water, should losses occur. Breakouts, aggravated by low mud weights, lost circulation events, high deviation and slim hole contributed to poor hole cleaning, which caused the packoff incidents in the 6 1/8" sections.
Safe and stable mud weight windows were established to mitigate hole collapse and stuck pipe. Since losses can occur even at low mud weights but do not usually have severe consequences, the team decided it was more important to focus on avoiding breakouts and improve hole cleaning with higher mud weights, improved drilling fluids with stress cage system to drill through depleted reservoirs, controlled drilling, ECD management to prevent formation breakdown and the use of Rotary Steerables to improve hole cleaning. The recommendations of the study were incorporated during a 3 well drilling campaign in 2009. All 3 wells were drilled and completed within budget and without stuck pipe incidents.
Effects of Antecedent GABAA Activation With Alprazolam on Counterregulatory Responses to Hypoglycemia in Healthy Humans
Authors: Hedrington Maka S. , Farmerie Stephnie , Ertl Andrew C. , Wang Zhihui , Tate Donna B. , Davis Stephen N. 
Published: January 2010

OBJECTIVE
To date, there are no data investigating the effects of GABAA activation on counterregulatory responses during repeated hypoglycemia in humans. The aim of this study was to determine the effects of prior GABAA activation using the benzodiazepine alprazolam on the neuroendocrine and autonomic nervous system (ANS) and metabolic counterregulatory responses during next-day hypoglycemia in healthy humans.

RESEARCH DESIGN AND METHODS
Twenty-eight healthy individuals (14 male and 14 female, age 27 ± 6 years, BMI 24 ± 3 kg/m2, and A1C 5.2 ± 0.1%) participated in four randomized, double-blind, 2-day studies. Day 1 consisted of either morning and afternoon 2-h hyperinsulinemic euglycemia or 2-h hyperinsulinemic hypoglycemia (2.9 mmol/l) with either 1 mg alprazolam or placebo administered 30 min before the start of each clamp. Day 2 consisted of a single-step hyperinsulinemic-hypoglycemic clamp of 2.9 mmol/l.

RESULTS
Despite similar hypoglycemia (2.9 ± 1 mmol/l) and insulinemia (672 ± 108 pmol/l) during day 2 studies, GABAA activation with alprazolam during day 1 euglycemia resulted in significant blunting (P &lt; 0.05) of ANS (epinephrine, norepinephrine, muscle sympathetic nerve activity, and pancreatic polypeptide), neuroendocrine (glucagon and growth hormone), and metabolic (glucose kinetics, lipolysis, and glycogenolysis) counterregulatory responses. GABAA activation with alprazolam during prior hypoglycemia caused further significant (P &lt; 0.05) decrements in subsequent glucagon, growth hormone, pancreatic polypeptide, and muscle sympathetic nerve activity counterregulatory responses.

CONCLUSIONS
Alprazolam activation of GABAA pathways during day 1 hypoglycemia can play an important role in regulating a spectrum of key physiologic responses during subsequent (day 2) hypoglycemia in healthy man.
Environmental tobacco smoke exposure and perinatal outcomes: a systematic review and meta‐analyses
Authors: SALMASI GISELLE , GRADY ROSHEEN , JONES JENNIFER , MCDONALD SARAH D. ,   On behalf of the Knowledge Synthesis Group*
Published: January 2010

AbstractBackground. While active maternal tobacco smoking has well established adverse perinatal outcomes, the effects of passive maternal smoking, also called environmental tobacco exposure (ETS), are less well studied and less consistent. Objective: To determine to the effect of ETS on perinatal outcomes. Search strategy. Medline, EMBASE and reference lists were searched. Selection criteria. Studies comparing ETS‐exposed pregnant women with those unexposed which adequately addressed active maternal smoking. Data collection and analysis. Two reviewers independently assessed titles, abstracts, full studies, extracted data and assessed quality. Dichotomous data were pooled using odds ratios (OR) and continuous data with weighted mean differences (WMD) using a random effects model. Main results. Seventy‐six articles were included with a total of 48,439 ETS‐exposed women and 90,918 unexposed women. ETS‐exposed infants weighed less [WMD –60 g, 95% confidence interval (CI) –80 to –39 g], with a trend towards increased low birthweight (LBW, < 2,500 g; RR 1.16; 95% CI 0.99–1.36), although the duration of gestation and preterm delivery were similar (WMD 0.02 weeks, 95% CI –0.09 to 0.12 weeks and RR 1.07; 95% CI 0.93–1.22). ETS‐exposed infants had longer infant lengths (1.75 cm; 95% CI 1.37–2.12 cm), increased risks of congenital anomalies (OR 1.17; 95% CI 1.03–1.34) and a trend towards smaller head circumferences (–0.11 cm; 95% CI –0.22 to 0.01 cm). Conclusions. ETS‐exposed women have increased risks of infants with lower birthweight, congenital anomalies, longer lengths, and trends towards smaller head circumferences and LBW.
Intramuscular manifestation of non-hodgkin lymphoma and myeloma: Prevalence, clinical signs, and computed tomography features
Authors: Surov Alexey , Holzhausen Hans-Jürgen , Arnold Dirk , Schmidt Jörg , Spielmann Rolf-Peter , Behrmann Curd 
Published: January 2010

Background: Intramuscular manifestations of malignant immunoproliferative diseases (IMMID) are very rare. Purpose: To determine the prevalence and the clinical features of IMMID in a large series of patients, and to analyze their radiological appearances. Material and Methods: Between 1997 and 2007, 20 patients with IMMID (non-Hodgkin lymphoma [NHL], n=14, and myeloma, n=6) were identified. All patients underwent computed tomography (CT). In five cases, magnetic resonance imaging (MRI) was additionally performed. Results: Clinically, 16 patients presented with local pain and soft-tissue swelling. In four patients, IMMID was found incidentally. The most common site was the erector spinae muscle, followed by the iliopsoas and pelvic muscles. In 13 cases of IMMID, diffuse mass-forming muscle infiltration was found. Focal intramuscular masses were identified in seven cases. Conclusion: NHL mostly manifests as diffuse muscle enlargement, whereas myelomas form focal intramuscular masses. Nevertheless, CT and MR appearances are nonspecific and can be misinterpreted as muscle sarcoma or inflammatory disease. Although rare, muscle involvement should be considered in the differential diagnosis of muscle disorders in patients with non-Hodgkin lymphoma and myeloma.
Feasibility of magnetic resonance angiography (MRA) follow-up as the primary imaging modality after coiling of intracranial aneurysms
Authors: Bakker Nicolaas A. , Westerlaan Henriette E. , Metzemaekers Jan D. M. , van Dijk J. Marc C. , Eshghi Omid S. , Mooij Jan Jakob A. , Groen Rob J. M. 
Published: January 2010

Background: Digital subtraction angiography (DSA) is still regarded as the gold standard for detecting residual flow in treated aneurysms. Recent reports have also shown excellent results from magnetic resonance angiography (MRA) imaging. This is an important observation, since DSA is associated with a risk of medical complications, is time consuming, and is more expensive. Purpose: To determine whether MRA could replace conventional DSA and serve as the primary postinterventional imaging modality in patients with coiled intracranial aneurysms. Material and Methods: We studied a prospectively enrolled cohort of 190 patients treated endovascularly for a first-ruptured and/or unruptured intracranial aneurysm between January 2004 and December 2008. The imaging protocol included a 1.5T time-of-flight (TOF) MRA and a DSA at 3 months (on the same day) and, depending on comparability, a 1.5T TOF-MRA or DSA 1 year after treatment. All images were evaluated by a multidisciplinary panel. Results: In 141/190 patients, both an MRA and DSA were performed after 3-month follow-up. In 2/141 patients (1.4%), (small) neck remnants gave false-negative MRA results. In one patient (0.7%), this led to additional neurosurgical clipping of the aneurysm. In 25/141 patients, future follow-up (>3 months) consisted of DSA because of various reasons. In 24/25 of these patients, primary MRA images alone would invariably have led to additional DSA imaging. Conclusion: The present study shows that 1.5T TOF-MRA is a feasible primary follow-up modality after coiling of intracranial aneurysms. Given our data, we now suggest that, in every patient with a coiled intracranial aneurysm, the first follow-up, 3 months after coiling, should be an MRA study. Only when this MRA is inconclusive (e.g., because of coil artifacts), or in the case of suspicion of recanalization, should DSA be performed additionally.
NEW DESCRIPTIONS OF LARVAE OF FOREST INSECTS, VI, SEMIOTHISA, PARAPHIA, PROTOBOARMIA (LEPIDOPTERA, GEOMETRIDAE)
Authors: McGuffin W. C. 
Published: January 2010

Egg: Ovate in shape, bluish green in colour, the surface divided by reticulations into small hexagonal areas. Laid singly on the needles of host tree.First Instar: Head width 0.23 mm. Body 2.0 mm. in length and 0.23 mm. in width Brownish green body with light brown head.Second Instar: Head width 0.5 mm. Body 4.6 mm. in length and 0.5 mm. in width. Body lined alternately with green and light green stripes. Spiracular line greenish white. Head brownish green.