Prospects for Commercial Bitumen Recovery from the Grosmont Carbonate, Alberta

Abstract

The last few years have seen the end of the Athabasca land play and the revival of interest in Alberta's bitumen resources in carbonate reservoirs. Of these, the Grosmont Formation is the most promising in terms of resource size and concentration. It is also the best known, in terms of having been the subject of several in situ pilots operated in the late '70s and early '80s.

The data recorded from these early pilots is priceless in terms of having a touchstone of reality for new process concepts. On the other hand, the interpretations written in those days ('before gravity') are not necessarily as helpful. This paper looks at the Grosmont in terms of facts and fundamentals, and presents the case for Grosmont exploitation.

There is good evidence that the Grosmont has very high bulk permeability as a result of karst porosity development and fracturing. This bodes well for the use of modern gravity drainage methods in the Grosmont.

Introduction

Grosmont Piloting History

The Grosmont Formation in north-central Alberta is a dolomitized, karsted and fractured platform carbonate containing a massive bitumen accumulation. An excellent historical summary of various Grosmont pilots was recently provided by Alvarez et al.(1) Cyclic Steam Stimulation (CSS), steam drive and forward combustion were all attempted in the Grosmont during the '70s and '80s. CSS was the most widely and successfully piloted method. The best well, at 10A-5-88-19W4, recovered about 100,000 bbls of oil over 10 cycles, with a cumulative steam-oil ratio (CSOR) of about 6. Results of other tests were mixed, as were the operating procedures; most of these were based on horizontal flooding concepts. However, responses to well-executed CSS first cycles were reasonably similar at a number of widely-spaced wells. Notably, steam injectivity was generally sufficient so that a few hundred tonnes/day could be injected at pressures that were significantly below overburden pressure (ruling out geomechanical enhancement of permeability).

A degree of pessimism, or at least great caution, has been expressed with respect to the supposed complexity of the reservoir, and hence, prospects for commercial recovery. In particular, it is often said that the reservoir is very heterogenous, and that this explains the historical failure of attempted steam drive and fire flood processes.

Review of the Unocal Buffalo Creek and McLean scheme reports(2, 3) suggest that much of this originates in the interpretations of the contemporary operators, who largely explored conventional EOR concepts involving horizontal displacement. They expected to recover oil by means of horizontal, radial flow. When this failed, it was natural to assume that the problem lay in a failure to maintain the 'radial' part of the prescription, due to permeability heterogeneity.

Figure 1 presents the performance of the Buffalo Creek 10A-5 CSS test in perspective with a contemporary test and two modern-day, commercially-optimized CSS wells (the data is publicly available from the Alberta Energy Resources Conservation Board). It can be seen that the Grosmont well had comparable performance to a Clearwater CSS test of the same vintage.

The Birmingham Epidermolysis Bullosa Severity score: development and validation

BACKGROUND

Objective severity scores facilitate clinical care and research. However, the rarity and heterogeneity of epidermolysis bullosa (EB) make scoring difficult.

OBJECTIVES

To develop a severity score covering all subtypes of EB at all ages that is simple, valid, sensitive and reliable.

METHODS

Score items and weightings were generated by expert consensus, and refined for content and face validity. The Birmingham EB Severity (BEBS) score was tested on 97 patients aged 0-64 years.

RESULTS

Eleven items were scored: area of damaged skin, involvement of nails, mouth, eyes, larynx and oesophagus, scarring of hands, skin cancer, chronic wounds, alopecia and nutritional compromise. Area was allocated 50 points, and the 10 other items 5 points each, giving a maximum score of 100. Lowest BEBS scores occurred in Weber-Cockayne EB simplex (median 1.0; range 0.1-3.0; n = 12), highest scores in generalized non-Herlitz junctional EB (28.5; 5.0-62.0; n = 7), Hallopeau-Siemens recessive dystrophic EB (HS-RDEB) (22.9; 4.3-69.0; n = 23) and Herlitz junctional EB (H-JEB) (14.4; 2.5-49.3; n = 9), and intermediate scores in dominant dystrophic EB (5.3; 0.5-15.9; n = 19), Dowling-Meara EB simplex (DM-EBS) (6.3; 2.8-22.5; n = 16) and non-Hallopeau-Siemens recessive dystrophic EB (7.8, 2.8-27.8; n = 11). Intra- and interobserver correlations were high. With age, scores increased for H-JEB (r = 0.9, P = 0.001) and HS-RDEB (r = 0.73, P = 0.001) and decreased for DM-EBS (r = -0.62, P = 0.01), with positive but nonsignificant correlations for the other types.

CONCLUSIONS

The BEBS score appears valid and reproducible, gives appropriate scores for different subtypes, and reflects changes with age.

Long-term outcome of asymptomatic patients with congenital cystic adenomatoid malformation

PURPOSE

Congenital cystic adenomatoid malformation (CCAM) represents a rare congenital anomaly of the lung. It remains controversial whether patients with asymptomatic lesions warrant early surgical intervention. Our aim was to review the outcome of asymptomatic CCAM patients at a paediatric tertiary centre.

METHODS

The medical case notes of all children with CCAM presenting to our institution between 1986 and 2007 were reviewed. Data on pre- and post-natal investigations, clinical presentation, lesion site, type of surgical procedure, timing, and outcomes of surgery were reviewed.

RESULTS

A total of 35 patients were diagnosed with CCAM during the 21-year study period (1986-2007). Sixty percent (n = 21) were asymptomatic at birth including eight patients with prenatal ultrasound scan confirming CCAM. In this group, 18 patients (86%) subsequently developed symptoms (median age 2 years, range 1 month-13 years) and required surgery. Symptoms included pneumonia with or without infected CCAM (43%), respiratory distress (14%) and spontaneous pneumothorax (14%). Eight patients underwent multiple hospital presentations with complications related to CCAM. Of the 21 initially asymptomatic patients, 17 (81%) underwent surgical resection. Only one of these patients was completely asymptomatic prior to surgery. There were eight post-operative complications and no mortality. One patient underwent a second thoracotomy for residual CCAM. The median length of hospital stay was 9 days (range 3-32 days).

CONCLUSION

This study suggests patients who present with asymptomatic CCAM will subsequently become symptomatic. Early surgical referral and intervention may be beneficial to avoid the development of complications.

Targeting brain tumor stem cells using a bispecific antibody directed against CD133+ and EGFRvIII+

2022

Background: Using the marker CD133, cancer stem cells (CSCs) have been demonstrated for glioblastomas (GBMs) and medulloblastomas. However, CD133 is also present on normal neural stem cells. EGFRvIII is a tumor specific EGF receptor. We hypothesized that a recombinant bispecific antibody directed against CD133 and EGFRvIII would be a highly specific reagent. Methods: Single chain antibodies (scFv) were cloned for anti-EGFRvIII and anti-CD133 using existing hybridomas and published sequences. scFv were cloned into a bicistronic vector containing a human CH3 constant domain. The bispecific antibody (BsAb) contains the anti-CD133 (AC133) and anti-EGFRvIII single chain Fv; monospecific but bivalent reagents for anti-CD133 and anti-EGFRvIII were also constructed. Results: U87 cells were co-transfected with increasing amounts of CD133 and decreasing amounts of EGFRvIII cDNAs. The BsAb showed the highest binding for cells expressing both epitopes, whereas Di-EGFRvIII and Di-AC133 had the highest affinity for cells expressing high levels of individual antigens. When cells expressing both antigens were mixed with cells expressing high levels of either antigen alone, the BsAb only recognized CD133+/EGFRvIII+ cells. We then explored the efficiency of tumor cell killing. Using human CD16-expressing NK cells as the effectors at an effector:target ratio of 10:1 and an 83 nM antibody concentration, the BsAb induced 86% lysis of U87-EGFRvIII/CD133 cells, 42.5% in U87-vIII but only 27.3% in U87-CD133 cells. Di-EGFRvIII efficiently induced cytotoxicity in U87-EGFRvIII/CD133 and U87vIII cells but not in U87-CD133 cells. Di-CD133 was the least effective at inducing ADCC. Finally, we studied the ability of the BsAb to induce ADCC on tumor spheres and normal neurospheres. The BsAb showed at least 4X greater lysis on tumor spheres that were CD133+/EGFRvIII+ over normal neurospheres expressing CD133 alone at an E:T of 10:1. This was seen at concentrations as low as 0.83 nM. Conclusions: A recombinant bispecific antibody directed against CD133 and EGFRvIII is highly specific for cells that are positive for both antigens, but poorly targets cells expressing CD133 alone. It can potentially be used as a therapeutic agent for specifically targeting CD133+/EGFRvIII+ cancer stem cells.

No significant financial relationships to disclose.

Trastuzumab and vinorelbine (TV) in early stages of breast cancer

e11556

Background: HER-2+ breast cancers (BCs) have a higher relapse rate, even for early stages of disease. The combination of trastuzumab and vinorelbine (TV) displays a high degree of synergism both preclinically and in metastatic BC patients that typically tolerate TV remarkably well. Occasionally, patients refuse standard treatment with chemotherapy and trastuzumab because of toxic side effects. In our institution, some of these patients accepted to receive treatment with TV. Methods: We retrospectively collected data on patients with stage I-III BCs, treated with TV as the only chemotherapy regimen. Most patients received TV on a weekly basis (one week off for V every 3–4 weeks) for ∼6 months, followed by 6 more months of T only. Results: Between May 2003 and June 2008, 23 patients were started on weekly TV. Median age was 66. Five patients received TV as preoperative treatment for BCs with the following clinical stages: IIB (1); IIIA (1); IIIB (3). The other 18 patients were pathologically staged as: stage I (11); IIA (5); IIIB (2). All cancers were HER2+; 65% of patients also received hormonal treatment for ER/PR+ disease. 3 patients had been previously treated for BC, and received TV as “adjuvant” treatment after a local relapse. Only one of these patients had previously received chemotherapy, while none had received prior T. No pathological complete response was found at surgery after preoperative TV. TV was very well tolerated, with one patient developing febrile neutropenia, 4 patients grade 3–4 uncomplicated neutropenia, and no other grade 3–4 events. During therapy, 5 patients had an asymptomatic 10–20% drop in the LVEF (Grade 1). Follow-up MUGA scans at 1 year after TV so far failed to show any significant abnormality. At an average follow-up of 26 months, one patient died for non-BC related causes, and all the other 22 patients are disease-free. Conclusions: TV is safe and very well tolerated, with no significant cardiac toxicity in our patient population. Preliminary follow-up data suggest that TV may be an acceptable alternative (neo-)adjuvant therapy for patients refusing “toxic” chemotherapy. Further studies prospectively testing TV as adjuvant treatment should be considered for patients with stage 1A BC, for which no standard treatment is clearly defined.

No significant financial relationships to disclose.

Long-term outcome of patients with a successful trial without catheter, after treatment with an alpha-adrenergic receptor blocker for acute urinary retention caused by benign prostatic hyperplasia

OBJECTIVE

To perform a retrospective review of long-term outcome for patients with a first episode of acute urinary retention (AUR) who could void successfully after the initial trial without catheter (TWOC) after treatment with an alpha-adrenergic receptor blocker (AR blocker).

METHODS

The records of 248 patients who presented with a first episode of AUR secondary to benign prostatic hyperplasia (BPH) and who could void successfully after the initial TWOC following treatment with an AR blocker were reviewed during the period January 1998 to December 2001. The characteristics of the patients and the subsequent outcomes were recorded. The primary outcome assessed was failed medical treatment within the five-year follow-up period. Factors correlated with the primary outcome were also assessed.

RESULTS

For these 248 patients, the median follow-up time was 33.0 months (range 0-96 months). The percentage of patients with failed medical treatment at 6, 12, 24, and 60 months was 11.6, 14.3, 28.4, and 50.5%, respectively. Multivariate analysis indicated that only a prostate size >50 ml and serum prostate specific antigen (PSA) level during AUR >10 ng/dl were significant predictors of subsequent requirement for surgical intervention after a successful TWOC.

CONCLUSIONS

Although AR blockers increased the success rate of TWOC, approximately half of the patients in this study still required additional intervention within five years. By using appropriate selection criteria, such as a large prostate size (>50 ml) or high serum PSA level during AUR (>10 microg/l), patients who are at greater risk of TWOC failure can be identified, and earlier surgical intervention can be offered to them.

A (59)Co NMR study to observe the effects of ball milling on small ferromagnetic cobalt particles

To demonstrate the potential of nuclear magnetic resonance (NMR) spectroscopy for investigating detailed structural properties in ferromagnetic materials, three different particle sized cobalt (Co) powders have been ball milled for 24h are accurately characterised by internal-field (59)Co NMR. The (59)Co NMR spectra show distinct resonance bands corresponding to the different Co sites, face-centred-cubic (fcc), hexagonal-close-packed (hcp) and stacking faults (sfs), in Co metal powders. The hcp+fcc-->hcp phase transition encouraged by ball-milling was observed and quantitative values for each Co environment were obtained.

Alanine aminotransferase levels are not significantly elevated in patients with HIV/HBV co-infection and lamivudine resistance

In hepatitis B virus (HBV) monoinfection, alanine aminotransferase (ALT) levels are linearly correlated with HBV DNA levels and lamivudine resistance. In human immunodeficiency virus (HIV)/HBV co-infection, little is known about the association between ALT, HBV DNA, and lamivudine resistance. We assessed HBV DNA, lamivudine resistance and ALT levels in 45 time points in 11 patients with HIV/HBV co-infection during lamivudine-containing antiretroviral therapy. High HBV DNA levels (>10(6) copies/mL) and lamivudine resistance developed in 45% and 91% of patients, respectively. However, ALT levels were not elevated in the setting of high HBV DNA levels (mean ALT, 48 IU/mL) or lamivudine resistance (mean ALT, 44 IU/mL). HBV viraemia and lamivudine resistance during extended lamivudine-containing antiretroviral therapy are common in HIV/HBV co-infection, occurring in the absence of significant ALT elevations. In HIV/HBV co-infection, measurement of HBV DNA and HBV resistance mutations may identify HBV virological failure before biochemical changes and should be routinely used in the management of HIV/HBV co-infection.

Genomics, Transcriptomics and Methylomics: Alternative Approaches for the Analysis of Serotonin System and Antipsychotic Response

Serotonin receptors blockade is the major basis for the action of atypical antipsychotic drugs. Genetic factors affecting the density and/or function of serotonergic receptors, transporters and enzymes may therefore affect antipsychotic response. This exploratory study investigates the effect of ten polymorphisms from HTR1A, HTR1D, HTR2A, HTR3A, HTR3B, HTR4, HTR6, SLC6A4, TPH1, TPH2 genes on antipsychotic response in a sample of 289 patients with DSM-diagnosis of schizophrenia. Clinical Response was assessed using Brief Psychiatric Rating Scale (BPRS). Response was determined as 20% reduction improvement of BPRS compared to baseline. Selection of the biological relevant interactions, regardless the phenotype was performed using different statistics strategies regardless the phenotype to investigate epistasis within the serotonin system. the test for relevant interaction selection showed that 5HT4 and 5HT6 can be in epistatic relationship. the single locus analysis of these two receptor polymorphisms showed no significant results and the logistic regression model incorporating both genes, the clinical and demographic variables was not significant. Even this result is not significant, this strategy aimed to investigate the epistatic effect among genes could be useful for finding relevant biological interaction among genetic variants. Furthermore we are currently analyzing the methylation level of HTR2A in responders and non-responders, this epigenetic analysis will be very valuable in adding more information to the classic pharmacogenetic studies.

Energy efficient medium access protocol for wireless medical body area sensor networks

This paper presents a novel energy-efficient MAC Protocol designed specifically for wireless body area sensor networks (WBASN) focused towards pervasive healthcare applications. Wireless body area networks consist of wireless sensor nodes attached to the human body to monitor vital signs such as body temperature, activity or heart-rate. The network adopts a master-slave architecture, where the body-worn slave node periodically sends sensor readings to a central master node. Unlike traditional peer-to-peer wireless sensor networks, the nodes in this biomedical WBASN are not deployed in an ad hoc fashion. Joining a network is centrally managed and all communications are single-hop. To reduce energy consumption, all the sensor nodes are in standby or sleep mode until the centrally assigned time slot. Once a node has joined a network, there is no possibility of collision within a cluster as all communication is initiated by the central node and is addressed uniquely to a slave node. To avoid collisions with nearby transmitters, a clear channel assessment algorithm based on standard listen-before-transmit (LBT) is used. To handle time slot overlaps, the novel concept of a wakeup fallback time is introduced. Using single-hop communication and centrally controlled sleep/wakeup times leads to significant energy reductions for this application compared to more ldquoflexiblerdquo network MAC protocols such as 802.11 or Zigbee. As duty cycle is reduced, the overall power consumption approaches the standby power. The protocol is implemented in hardware as part of the Sensiumtrade system-on-chip WBASN ASIC, in a 0.13- mum CMOS process.

A natural abundance (77)Se solid-state NMR study of inorganic compounds

Various inorganic selenium-based compounds were analysed by (77)Se solid-state NMR, and a distinct difference in chemical shift ranges for compounds where selenium is present as selenide (Se(2-)) ionically and covalently bonded systems was observed. The selenides exhibit a shift range of approximately -700 to -100ppm, as opposed to 700 to 1600ppm for the compounds where there tends to be more direct covalent bonding to the selenium. The anisotropic hyperfine shift observed in NbSe(2) is shown to be axially symmetric, where the H(11) component is found to be normal to the Se3-trigonal plane.

Molecular and genetic characterisation of the SARS coronavirus auxiliary protein X1 in Drosophila

1. We have generated monoclonal antibodies against the SARS coronavirus (SARS-CoV) X1/3a protein (3a), which are suitable for western blotting, immunocytochemistry, and immunohistochemistry. 2. We have established and characterised an in-vivo 3a transgenic Drosophila model, and demonstrated its usefulness in studying SARS-CoV 3a gene function. 3. We validated our in-vivo findings on 3a gene function in mammalian Vero E6 cells. 4. Our findings raise the possibility of using ion channel blockers as a novel approach to suppress SARS-CoV-induced cell death.

Evaluation of strategies to improve nutrition in people with dementia in an assessment unit

OBJECTIVES

To evaluate strategies designed to improve nutrition in elderly hospitalised patients with dementia.

DESIGN

Observation phase followed by sequential interventions.

SETTING

A Short stay assessment unit.

PARTICIPANTS

Hospital Inpatients with a variety of conditions causing dementia.

INTERVENTIONS

Phase 1: Observation. Phase 2: Encouraging dietary, 'Grazing'. Phase 3: Using volunteers to feed patients. Phase 4: Improving dining room ambience by playing soothing music.

MEASUREMENTS

Body Mass Index (BMI), mid arm circumference, mini nutrition index and caloric intake by plate waste measurement.

RESULTS

BMI fell in the Observation phase 0.6 +/- 0.68 kg/m2 (p < 0.001), but increased in each of the Intervention phases. Phase2 0.3 +/- 0.86 kg/m2 (p < 0.04), Phase 3 0.37 +/- 0.4 kg/m2 (p < 0.04), Phase 4 0.39 +/- 0.7 kg/m2 (p < 0.007). Caloric intake increased in the intervention phases.

CONCLUSIONS

Simple, inexpensive and easy to implement strategies can improve nutrition in hospital inpatients with dementia.