bluuebunny/crossref_metadata_2025_split huggingface dataset:
Heavy Oil-"Riding the Wave"
Authors: Morgan Rob 
Published: March 2010

This month we will be presenting our fifth year of the one day "Slugging it Out" conference series. Co-sponsored by the Heavy Oil Special Interest Group and the Canadian Heavy Oil Association, this successful series gathers individuals interested in all areas of heavy oil development for an informal and informative brainstorming ession. our theme this year is "Riding the Wave," which we feel is very appropriate given the resurgence in heavy oil activity, primarily due to heavy oil wellhead prices in the $20/bbl range. The conference will be held at the Metropolitan Centre on April 10 and registration information is available by contacting The Petroleum Society office. Now that I've dispensed with the commercial, let's consider the last 12 years of our heavy oil industry.
I believe this is my second major price cycle in the heavy oil business. As a production engineer in Lloyminster in 1985, it appeared that all that was required to make money was to get oil out of the ground, by whatever means possible. Wellhead prices for heavy oil were in the $30/bbl range, and economic analysis would support drilling a 20 bopd well. Price forecasts were of the "hockey stick" variety, and the majors were amassing infrastructure to be ready when prices hit $50/bbl. Thermal projects (primarily Cyclic Steam Stimulation) were in full operation predicting 30% recovery of the original oil in place. A conventional vertical primary well was drilled on 40 acre spacing and the rule of thumb recovery factor was 5%. Sand production was a necessary evil that contributed to higher operating costs and could sometimes be mitigated by reducinghe drawdown on your well. Progressive (or as they are more correctly called now Progressing) Cavity Pumps had appeared on the scene, but were generally not accepted as a means of producing heavy oil.
The decision by OPEC in early 1986 to recapture market share lost over the years was a dramatic "wake-up" call to our industry. By mid to late 1986, a barrel of heavy oil in Lloydminster was selling for less than $10 and companies were scrambling to minimize the losses. The first to go were the thermal projects as operating costs were typically in excess of $10/bbl. Next, the marginal primary producing wells were shut-in. The human toll was most obvious as the vacancy rate at my apartment complex went from 0.1 % to 30% in a matter of eight months. Throughouthis process, I realized that I had very little understanding of the factors that influenced the pricing of heavy oil, and perhaps it was time to remedy that situation.
Pricing for heavy crude is based on a differential to a light sweet crude (usually the Edmonton par price for a 40 API crude) which encompasses differences in quality (density and sulfur content) and the amount of condensate (C5+) required to make up a heavy oil blend suitable for pipelining. A Lloydminster type blend is typically in the order of 22 API and will contain anywhere from 20 – 25% condensate.
Can Snake Oils Become Panaceas?
Authors: Davis Gordon A. 
Published: March 2010

At just about any time during the course of recent history, in the "oil patch," there have been processes or "technologies" which for one reason or another did not fit the paradigm of the time, and in many cases were branded as radical, extreme, unwarranted or even dangerous, as they had not either been sufficiently developed or tested to everyone's satisfaction. In many cases, some were even considered "snake oil," as they seemed to work, but no one could say why, and in many cases the results were short-term or not at all.
And so it goes, in the ever present struggle by producers to increase field productivity. So many possibilities, all of which would take a part of the profits from current production, while promising future increases.
For many of these technologies, success and acceptability came from the acceptance of the process by some forward thinking, established service company which decided to invest in the process, and even to improve or develop it through genuine research projects, lack of such acceptance resulted in failure and obscurity. Such is the case even today, with many applications which can and in many cases do, improve productivity substantially, using unconventional or even unorthodox methodology. In all of the problems faced daily by producers, two of the major ones in the current market are: formation/perforation damage, and waxing and scaling.
Formation/perforation damage which occurs to the formation from initial drilling and fluid invasion thereby reducing effective porosities and permeabilities, or damage which occurs from perforating, such as reduced core flow efficiencies, have always been problems, which have required many different approaches in as many situations. However there now appears to be a consistent application which can help.
Historically, explosive stimulation has always been treated as one of those "snake oil" methods which worked in many cases, and not in just as many, with no real way of telling where it would or would not. In too many cases, not only did it not, but many times it also caused significant and irreversible damage in the process.

Little Wonder in the Lack of Faith by the Industry
In recent years, however, significant scientific investigation, and improvements both in the method and materials (low detonation velocity epoxies) have significantly increased the efficiency of propellant stimulation technology. More important still, the ability to model and simulate the stimulation technique have been developed and refined, and high speed impact resistant data recorders have been developed which can measure and record the event. By simulating the event and using precisely calculated amounts of propellant, and by analysing the data recorded, an effective, repeatable stimulation can be obtained. With this sort of control and predictability, many companies have decided to use propellant stimulation, in a variety of applications, rom heavy oil perf clean up and sand-arch collapse, to prefrac treatments of sandstones and carbonates, all with a good deal of success.
Patterns And Structural Positions of Productive Fractures In the Asmari Reservoirs, Southwest Iran
Authors: Gholipour A.M. 
Published: March 2010

Abstract
In wrench faulted areas, similar to the one introduced here, identifying structural styles and their histories could be one of the most important tasks in studying tectonic related fractures and faults.
The main purpose of this paper is to examine the patterns and structural positions of productive fractures in different reservoir structures of the Asmari formation (Oligo-Miocene) in the Khuzistan oil fields belt of southwest Iran.
Details of productive fracture positions have been studied on four major Asmari reservoirs, using:production data (e.g., production rates and productivity indices) which are the most reliable indirect fracture identifiersmud losses, to identify open fracture portionfaulted well assemblages to find tectonically active Portionssecond derivative map to find the portions of the maximum rate-of-change-of-dip on top of the reservoir structures, where it is expected to have maximum fracture density.
The results were then compared with the surface fracture patterns and densities in the mountain front boundary in the area.
In general, productive fractures were found to be associated mainly with the plunges and bends of the Asmari reservoir structures.
To assist in determining optimal horizontal well trajectories in the anticlinal traps of the studied area, idealized fracture pattern models have been presented in this paper.

Structural Styles and History of the Area
Identifying structural styles and their histories could be one of the most important tasks in studying tectonic related fractures. These styles are generally differentiated on the basis of the extent of the basement involvement and/or the detachment of sedimentary cover.
In the Khuzistan oil fields belt of southwest Iran, reservoir structures have become further complicated by the superimposition of fundamentally different tectonic regimes, which are still active based on a high concentration of earthquake foci in the area (Figure 1).
Some evidence of recent activity of the regional basement controlled faults is indicated by a high concentration of the earthquake epi-centres (foci), the existence of sinuosity (bending) in the reservoir structures and high length to width ratio in most of the anticlinal structures of the Plio-Pleistocene age.
The major deformation took place in the Miocene, following the collision of the Arabian plate with the central Iranian block. This convergence, with its accompanied subduction, caused the folding of sedimentary cover into the present styles; huge anticlines, with general trends of northwest-southeast perpendicular to orogenic (folding) compressional forces which are southwestnortheast trending.
These styles are mostly formed during three different stages:Early orogenic shocks, which caused the early folding phase in the Miocene.Main orogenic shocks, which caused the late folding phase in the Pliocene.Recent orogenic shocks, which caused the recent folding phase.
Each folding phase created its own related fracture pattern, which are discussed in this paper.
Flare Gas Flow Rate Measurement By a Steady State Tracer Dilution Method
Authors: Tang J.S. 
Published: March 2010

Abstract
A tracer dilution method based on steady-state tracer concentration at constant injection rate has been designed and implemented successfully at Imperial Oil's Quirk Creek gas plant to measure flare gas flow rate which, together with the H2S content, is required for renewing the clean air operating licence. The gas flow rate was determined to be 2.06 ± 0.05 Sm3/min or 2.48 ± 0.05 m3/min at the stack conditions, and the H2S concentration was averaged at 13.7 ± 2.9% over a period of six hours. The results agree with those obtained by simulation and mass balance. This is the first known reliable method for measuring flare gas flow rate in a low pressure, low flow rate and extremely sour environment. The method is well suited to accurate measurement of gas, oil, water flow rates in refining as well as production facilities. Complications due to tracer partitioning into the discharged liquid and dissimilar gas and tracer allocations in a complex flow field are discussed. A method for simultaneous measurement of flare gas and liquid discharge rates in a liquid knock-out tank using partitioning tracers is also presented.

Introduction
In the Quirk Creek gas plant, sour glycol and produced water constitute the two major sources contributing H2S to the flare gas stream. In the gas sweetening unit, sour gas is dehydrated by glycol before entering the amine absorber. The dissolved sour gas and water vapour are removed from the spent glycol in a subsequent glycol re-generation cycle. The separated gas is combined with the sour produced water overhead gas and gases from various other sources and then piped to a liquid knock out tank. This mixed gas stream which has a H2S content as high as 40% is flared with a valid clean air operating licence. The current licence was to expire in May 1993 and, in accordance with the government regulations, the daily sulphur emission rate has to be included in the licence renewal application. Sulphur emission calculation requires the knowledge of H2S concentration and the flare gas flow rate. While the H2S content can be accurately measured by gas chromatograph, there is no suitable gas flow meter which can be used in a low pressure, low flow rate and highly hazardous environment. A tracing method was thus developed by for measuring gas flow rate at such conditions.

Theory
Gas flow rate can be determined by a steady-state tracer dilution method. A gas tracer with high vapour pressure which can completely flash into the gas phase is injected at a constant rate into the gas stream and the tracer concentration is monitored downstream of the injection point, preferably near the gas outlet. The gas flow rate can be derived from the steady-state tracer concentration and the tracer injection rate. The tracer dilution method has been used successfully in measuring gas flow rate through compressor(1). The tracer results agreed with those measured by orifice flow meters within an accuracy of ± 1%.
The Steam And Gas Push (SAGP)
Authors: Butler R. 
Published: March 2010

Abstract
While heavy oils can be produced by horizontal wells at economic rates, the extent of recovery is small because of loss of drive and/or watering out of the production. In typical cases a recovery of only a few per cent of the OOIP is achievable. SAGD overcomes these problems by allowing high production rates with only a small drawdown. The reservoir pressure is maintained by the injection of the steam and operation without steam coning is practicable; very high recoveries are normally obtained.
In conventional SAGD the depleted reservoir becomes filled with steam at the saturation temperature corresponding to the operating pressure-typically 200 to 250 ° C. Large quantities of steam are required to heat the depleted reservoir, the reservoir surrounding the steam chamber and, particularly with thin reservoirs, the overburden. With high quality, thick reservoirs SORs of about 2.5 - 3 are obtained but in thinner reservoirs, and in reservoirs with lower oil saturations, SORs are much higher and the process is uneconomic. The problem is compounded by the steam chamber having long sloping boundaries that extend the heated area.
In this paper it is shown that it is not necessary for the whole steam chamber to be at a uniform high temperature. Only the lowest part, where the coning tendency is greatest, needs to be at the highest temperature. High temperatures in the upper part of the chamber are an "overkill" that results in wasted heat. It is proposed that the SAGD process be modified by injecting noncondensible gas, such as natural gas, with the steam from a horizontal injection well somewhat above the producer. Gas accumulates in the chamber above the injector and lowers the temperature. Considerable savings can be made by this approach without a substantial decline in performance. In one example it is shown that the heat stored in the chamber per cubic metre of produced oil will be only 62% of that for conventional SAGD and that the heat lost to the overburden will be a very much smaller fraction. This concept should greatly extend the range of reservoirs that can be produced economically.

Introduction
For the efficient and economic recovery of heavy oils it is necessary to employ means for facilitating the flow of the viscous fluid through the reservoir. Not only is it necessary to offset the effect of very high oil viscosity by providing extended contact and/or viscosity reduction by heating, but it is also necessary to maintain the drive needed to move the oil as the reservoir becomes depleted.
Some approaches such as the use of long horizontal wells or cyclic steaming are effective in promoting flow but only produce limited recovery. Steamflooding and, more recently, SAGD also maintain reservoir drive and allow high recoveries. However, because of their considerable heat requirements, these processes are limited in their economic use to higher quality reservoirs.
It is the purpose of this paper to describe a new concept for the production of heavy oils that is a modification of the SAGD process(1–5).
Successful treatment of juvenile pemphigus foliaceus in a Nigerian Dwarf goat
Authors: Cornish Jennifer , Highland Margaret 
Published: March 2010

Abstract
Case Description—A 2-month-old female Nigerian Dwarf goat was evaluated for a generalized crusting dermatitis; signs of depression; and fever of 1 month's duration.
Clinical Findings—Histologic evaluation of skin biopsy specimens revealed subcorneal pustules and rafts of acantholytic cells. No etiologic agents were detected in the biopsy material, and bacterial culture of skin biopsy specimens yielded no growth of pathological organisms. A diagnosis of pemphigus foliaceus was made.
Treatment and Outcome—Remission was achieved with a combination of SC administration of dexamethasone and IM administration of gold sodium thiomalate. The goat remained free of clinical signs for at least 26 months after discontinuation of all medications. No clinically apparent adverse effects of treatment were evident.
Clinical Relevance—This report represents the first description of successful treatment of juvenile pemphigus foliaceus in a goat by use of a novel protocol involving dexamethasone and gold sodium thiomalate.
Femtosecond Thin-flap LASIK for the Correction of Ametropia After Penetrating Keratoplasty
Authors: Barequet Irina S. , Hirsh Ami , Levinger Samuel 
Published: March 2010

PURPOSE:
To evaluate the outcomes of LASIK with thin femtosecond laser flaps for the treatment of refractive errors after penetrating keratoplasty (PK).

METHODS:
Eleven consecutive eyes underwent femtosecond thin-flap LASIK 51.6±42.1 months (range: 13 to 156 months) after the initial PK. A full ophthalmic assessment was performed before femtosecond LASIK and 6 months after surgery. Postoperative retreatments were also noted.

RESULTS:
No intra- or postoperative complications were observed. The outcomes of nine eyes that completed at least 6 months' follow-up and had no retreatment during that period were evaluated. Mean preoperative myopia decreased from −3.60±1.60 diopters (D) to +1.00±2.70 D 6 months after surgery, and mean hyperopia decreased from +3.50±1.30 D preoperatively to +0.30±0.70 D 6 months after surgery. Mean preoperative astigmatism decreased from −6.60±3.60 D to −2.90±2.00 D 6 months after surgery. At 6 months, the mean preoperative myopic spherical equivalent refraction (SE) decreased from −6.40±2.00 D to −0.02±2.20 D, and mean hyperopic SE from +0.80±2.80 D to −0.60±0.60 D. At 6 months postoperatively, 67% (6/9) of eyes were within 1 line of preoperative best spectacle-corrected visual acuity and 33% (3/9) gained ⩾2 lines.

CONCLUSIONS:

Femtosecond thin-flap LASIK is a safe procedure in eyes with previous PK. This procedure is reasonably predictable, especially for the spherical component of the refraction. Creating the flap with the femtosecond laser and performing excimer laser ablation within the corneal graft limits without involving the graft–host junction provides the advantage of performing the entire procedure in one step. [
J Refract Surg.
2010;26:191–196.]
The use of combined physiological parameters in the early recognition of the deteriorating acute medical patient
Authors: Cuthbertson BH , Boroujerdi  , Prescott G 
Published: March 2010

Background: Early warning scores (EWS) are widely used to allow early recognition of the deteriorating patient. We aimed to test their ability to predict major deterioration in medical patients. Methods: Two cohorts were prospectively identified who were admitted to an acute medical admissions unit and to the respiratory unit but not admitted to the intensive care unit (ICU): medical-non ICU and respiratory-non ICU groups. Two further cohorts were retrospectively identified that required ICU admission from these units (medical-ICU and respiratory-ICU groups). Discriminant analysis and receiver operating characteristic curves were used to discriminate between groups, and time relationships were analysed. Results: Heart rate (HR), respiratory rate (RR) and oxygen saturation (SaO2) were significantly higher in the medical-ICU group than the medical-non ICU group and significantly higher in the respiratory-ICU group than in the respiratorynon ICU group. Discriminant functions incorporating HR, RR and SaO2 performed at least as well as existing EWS systems in predicting ICU admission. Conclusions: Commonly used physiological parameters and existing EWS systems are useful at identifying sick patients. The discriminant functions described here appear to have a role in this setting but require validation in future studies.
The Sodium PotassiumATPase
Authors: Nyblom Maria , Morth Jens Preben , Nissen Poul 
Published: March 2010

AbstractAt the expense of adenosine triphosphate (ATP), the P‐type ATPase family of membrane proteins actively transports different cations or lipids, in a reaction cycle that includes the phosphorylation/dephosphorylation of a conserved aspartate residue. These proteins share a common structural and mechanistic core, but Na+, K+‐ATPase is the first multisubunit P‐type ATPase to be structurally determined. The Na+, K+‐ATPase exports three Na+‐ ions per ATP molecule from the cytoplasm, while at the same time transporting two K+‐ ions in the opposite direction. This electrogenic pump is critical for human and animal cells where the gradients of these ions are important for maintaining the resting potential and for electrical excitability of e.g. muscle and nerve cells, and for energization of secondary transporters and osmotic control. This article reviews the currently available structural knowledge of the Na+, K+‐ATPase. Hitherto, there are only structures of one of the catalytic forms reported representing the potassium‐occluded state ([K2]E2·Pi). The overall architecture of the αβγ‐complex is presented and the differences compared to the previously characterized structures of the sarco(endo)plasmic reticulum Ca2+‐ATPase (SERCA) are pinpointed. Furthermore, the properties of the K+‐ion binding sites are described and the functional relevance of the C‐terminus is addressed.
Structure, Spectroscopy, and Function of Tyrosinase; Comparison with Hemocyanin and Catechol Oxidase
Authors: Tepper Armand W J W , Lonardi Emanuela , Bubacco Luigi , Canters Gerard W 
Published: March 2010

AbstractThis article deals with tyrosinase, an enzyme that converts monophenols into diphenols and subsequently into orthoquinones with concomitant use of molecular oxygen as the source of oxygen atoms and oxidizing equivalents. The enzyme occurs widespread in nature. Its active center consists of a dinuclear copper site. The occurrence of tyrosinases and their biological function is reviewed. Information about primary (aa sequence, genetic organization), secondary, and tertiary structures is reviewed and, where appropriate, compared with similar information about related proteins with a dinuclear Cu site (hemocyanins, catechol oxidase). Methods to produce and purify tyrosinase are reviewed. Spectroscopic studies (optical; EPR, NMR, EXAFS) are reviewed in relation to the enzyme mechanism, which is discussed at the end of the article.