bluuebunny/crossref_metadata_2025_split huggingface dataset:
Successful Application of Hot Water Circulation in the Pelican Lake Field - Results and Analyses of the E29 Hot Water Injection Pilot
Authors: Duval Kirk , Gutiérrez Dubert , Petrakos Dino , Ollier Pierre , Johannson Darren 
Published: May 2015

Abstract
The Pelican Lake field in northern Alberta (Canada) is home to the first successful commercial application of polymer flooding in higher viscosity oils (i.e. greater than 1,000 cp), which has opened up new opportunities for the development of heavy oil resources.
The field produces from the Wabiskaw “A” reservoir which has thin pay (2 to 6 meters) and exhibits a significant viscosity gradient across the field, with oil viscosities as low as 600 cp in the existing waterflood and polymer flood area to over 200,000 cp in the current undeveloped “immobile” area. This unique geological feature limits the application of chemical injection to the less viscous areas of the field and calls for different methods for the heavier accumulations.
As a first step to develop alternate technologies capable of recovering oil from heavier areas of the field not ideal for polymer flooding, a hot water injection pilot was designed and implemented in June 2011. The hot water injection scheme was applied to a transition area where dead oil viscosity ranges from 3,000 cp to approximately 15,000 cp. It consists of one horizontal producer supported by two horizontal hot water injectors, with an injector-producer distance of 50 meters for both injectors, and 3 vertical observation wells equipped to monitor pressure and temperature between one injector and the producer.
The pilot was operated in three phases. The first phase consisted of 6 months of primary production period to obtain a baseline of the pilot performance prior to hot water injection. The second phase began in June 2011 and consisted of hot water injection through the edge injectors. The third phase was started in March 2012 and consists of hot water edge injection accompanied by hot water circulation in the production well as a means to stimulate oil production. One of the features of this stage is the use of an insulated coil tubing, which continuously delivers hot water to the toe of the producer and allows continuous stimulation and uninterrupted oil production.
This paper describes the mechanical components of the pilot and discusses the results obtained with an emphasis on the hot water circulation stage which has proven to be very effective. Oil production increased from approximately 6 m3/d during the flood stage, to more than 25 m3/d during the hot water circulation stage and has held relatively steady for more than 2 years.
The data captured has been reconciled with analytical and reservoir simulation models, and results suggest that the technology could help unlock some of the heavier oil accumulations in the field.
Modelling of Non-Condensable gas Injection In SAGD Process - Important Mechanisms And Their Impact On Field Scale Simulation Models
Authors: Nourozieh Hossein , Ranjbar Ehsan , Kumar Anjani 
Published: May 2015

Abstract
Field-scale simulation of non-condensable gas injection in a hybrid SAGD process for the heavy oil and bitumen reservoirs requires a comprehensive numerical model that considers different mechanisms involved in the processes. The complexity of modelling such processes is due to the interrelation of oil-gas phase behavior and fluid transport mechanisms such as advection, dispersion, and dissolution. The non-condensable gas in the vapour phase is transported into the reservoir by the advection process which is dominantly controlled by the rock-fluid interaction parameters.
The steam and non-condensable fluid in the gaseous phase may have different relative permeability and end-point saturations associated with their interaction with oil/liquid. The diffusion and dispersion of non-condensable gas control how it spreads within a phase and its dissolution into oil and water determines its transfer across phases. Although, it is still debated that non-condensable gas accumulates at the steam front reducing heat transfer into the oil phase and lowering oil production rate, some field production data show contrary results. That is, the co-injection of non-condensable gas with steam does not affect the oil production rate while it reduces the steam-oil ratio. The non-condensable gas may accumulate at the top of the reservoir providing an insulation effect, reducing heat losses to the overburden and increasing the thermal efficiency of steam.
This study attempts to provide insights about field scale simulation of non-condensable gas injection in the hybrid SAGD process with a comprehensive numerical simulation model. Analysis will be presented regarding important mechanisms that should be considered, their impact on the process, and techniques to model them. Some of the important mechanisms that will be discussed are diffusion and dispersion, and solubility of gas in bitumen and water. The intent is to identify factors important to the modeling of these processes at field scale and how robust simulation models can be developed to replicate observed field behaviour.
InSAR Natural Reflector Survey for Surface Heave and Steam Chamber Monitoring at a SAGD Site
Authors: Tang K. , James B. R. , Aguado V. 
Published: May 2015

Abstract
This paper presents a case study of the application of an Interferometric Synthetic Aperture Radar (InSAR) natural reflector (NR) survey to monitor surface heave and steam chamber growth at one of Suncor's steam assisted gravity drainage (SAGD) fields. InSAR is a satellite technology mainly used to monitor ground motion. An InSAR NR survey relies on back scattered signal from the ground surface itself as opposed to fixed corner reflectors (CRs) which are metallic trihedrals specially designed to reflect a radar signal. This allows a NR survey to cover large areas of ground compared to those carried out using corner reflectors, but at a lower accuracy. As such, InSAR NR surveys provide a potential way of monitoring surface heave that covers much of a SAGD field at very low cost.
Results from the NR survey are very promising. First, the trends in the surface heave measured by the NR survey were almost as accurate as those measured by the CRs. In addition, the NR survey provided useful data over about 50% of the target area. This dense coverage was unexpected since the test site is covered by small trees and extensive areas of muskeg, which will interfere with the reflected radar signal.
Reliable surface heave estimates could be made in topographically high areas and in areas with gentle slopes because of their drier nature. By contrast low lying areas that were generally wetter provided little to no reliable data, hence masking any surface heave.
Benchmarking of InSAR NR data to temperature fall offs found that the NR measured heave compared well to steam chamber conformance on overall average trends. In addition, manually measured heave also compared well to steam chamber growth measured by 4-D seismic. In conclusion, results indicate that an InSAR NR surface heave survey provides a promising way of measuring surface heave and steam chamber growth over large areas of SAGD fields. It is complementary to 4-D seismic, but at as little as one hundredth of its cost.
One of the limitations of a NR survey is that measurements must be taken in non-snow time. Areas of denser forest cover may not provide as much spatial coverage with NRs as was found at the target region discussed in this paper. InSAR coverage in these areas could be done using CRs.
New Insight on Carbonate Heavy Oil Recovery: Pore Scale Mechanisms of Solvent Alternating CO2 Foam/Polymer Enhanced Foam Flooding
Authors: Telmadarreie Ali , Trivedi Japan 
Published: May 2015

Abstract
Carbonate reservoirs, deposited in the Western Canadian Sedimentary Basin (WCSB), hold significant reserves of heavy crude oil that can be recovered by non-thermal processes. Solvent, gas, water, and water alternating gas injections are the main methods for carbonate heavy oil recovery in the WCSB. Due to the fractured nature of carbonate formations, many advantages of these production methods are usually contrasted by their low recovery factor. Alternative processes are therefore needed to increase oil sweep efficiency from carbonate reservoirs. Foam/polymer enhanced foam (PEF) injection has gained interest in conventional heavy oil recovery in recent times. However, the oil recovery process by foam, especially PEF, in conjunction with solvent injection is less understood in fracture heavy oil carbonate reservoirs. The challenge is to understand how the combination of surfactant, gas, and polymer allows us to better access the matrix and efficiently sweep the oil.
This paper introduces a new approach to access the unrecovered heavy oil in fractured carbonate reservoirs. CO2 foam and CO2 PEF were used to decrease oil saturation after solvent injection, and their performance was compared with gas injection. A specially designed fractured micromodel was used to visualize the pore scale phenomena during CO2 foam/PEF injection. In addition, the static bulk performances of CO2 foam/PEF were analyzed in the presence of heavy crude oil. A high definition camera was utilized to capture high quality images.
The results showed that in both static and dynamic studies the PEF had high stability. Unlike CO2 PEF, CO2 foam lamella broke much faster and resulted in the collapse of the foam during heavy oil recovery after solvent flooding. It appeared that foam played a greater role than just gas mobility control. Foam showed outstanding improvement in heavy oil recovery over gas injection. The presence of foam bubbles was the main reason to improve heavy oil sweep efficiency in heterogeneous porous media. When the foam bubbles advanced through pore throats, the local capillary number increased enough to displace the emulsified oil. PEF bubbles generated an additional force to divert surfactant/polymer into the matrix. Overall, CO2 foam and PEF remarkably increased heavy oil recovery after solvent injection into the fractured reservoir.
The results of these direct visualization experiments improve our understanding of the heavy oil recovery process by solvent alternating CO2 foam/PEF flooding in fractured reservoirs. Besides enhancing oil production, application of CO2 foam/PEF may require the injection of a lesser amount of solvent into the reservoir, providing economic and environmental advantages.
Case Study of Flue Gas Assisted SAGD in Offshore Heavy Oil Reservoirs
Authors: Zhao Shunqiang , Sun Yongtao , Sun Yubao , Wu Yongbin , Liu Xueqi 
Published: May 2015

Abstract
A large number of heavy oil deposits in Bohai Bay in China are deep (&gt;1500m) and extra-viscous (&gt;20000mPa.s@50°C), which are not feasible for conventional thermal recovery methods. For these reservoirs, co-injection of steam and flue gas directly from steam generator to carry out CSS has been proven successful by pilot tests. While the oil recovery factor of CSS is estimated to be less than 20%, which poses a high economic risk under offshore condition. In order to massively enhance the recovery factor, the Flue gas or multi-component thermal fluid assisted SAGD (MCTF-SAGD) was designed, and this paper discusses the reservoir engineering design, the deployment of pilot well pairs and the field application performance prediction.
Selection of a Chemical EOR Strategy in a Heavy Oil Reservoir Using Laboratory Data and Reservoir Simulation
Authors: Fortenberry R. , Suniga P. , Mothersele S. , Delshad M. , Lashgari H. , Pope Gary A. 
Published: May 2015

Abstract
Chemical enhanced oil recovery (CEOR) of heavy oils is growing in volume and scope due to advances in the technology and field experience. This work describes a new methodology to select a CEOR strategy in a heavy oil reservoir when several viable options exist. We applied this methodology to the Pelican Lake field in Alberta.
We evaluated water flooding, polymer flooding, alkaline-surfactant-polymer (ASP) flooding, alkaline-co-solvent-polymer (ACP) flooding and polymer flooding followed by ASP flooding in laboratory tests. We executed new experiments including microemulsion phase behavior, polymer rheology and corefloods representing these various strategies. These experiments were designed to help understand the role of mobility control in chemical flooding of heavy oils. UTCHEM, the University of Texas Chemical Flooding Simulator, was used to model experimental results, and to scale them up in pilot simulations using heterogeneous geological models representative of Pelican Lake.
We report results for the selection of promising CEOR strategies for implementation in Pelican Lake based on the new laboratory experiments, reservoir simulations and our qualitative understanding of their various advantages and disadvantages. We present simulation results of a pilot using horizontal wells in a heterogeneous geological model representative of the reservoir. We simulated the various chemical EOR processes using the matched experimental data and evaluated them in terms of total oil production, time to completion and complexity. In-situ oil viscosity and operational injection limits were evaluated as crucial sensitivities. We make recommendations for CEOR implementation based on simulation study results and our understanding of relative process risks and costs.
Global Well Completion Reliability Databases and their Use in Well Design
Authors: Sparke Simon J. 
Published: May 2015

Abstract
Tullow Oil has been very successful exploring both onshore Kenya and Uganda and in deepwater Ghana, and as a result planning for major development projects got underway. In East Africa it is planned for hundreds of wells to be operated using artificial lift with waxy oil, deviated wells and sometimes quite shallow with reservoirs around 750 M. In Ghana well reliability is critical due to the prohibitive re-entry costs in the event of completion component failures operating in water depths up to 7,0 ft.
Therefore the need to benchmark well designs and component selection and plan the support mechanisms around realistic mean time to failure and other well operating risk factors is a crucial input process for the field development plans.
Today, the global well count is in the order of 2,000,000 wells and includes all well types from oil/gas producers, water/gas injectors to water disposal wells. Given the cost of drilling wells and the additional costs and risks involved in maintaining well stocks over the full well lifecycle, one would expect the oil and gas industry to think like other reliability focussed industries such as aircraft manufacturing / operating. Sharing data should be the norm especially as operators have a strong desire to maximise production by minimising the number of well interventions through the selection of the most suitable and reliable well equipment.
Logically when enquiring about equipment reliability, this should start with the equipment provider(s), however, they are understandably biased and not in a position to provide an objective and comparative answer as they are in competition with other equipment providers.
However, given this bias, an independently managed reliability database containing data for many hundreds of thousands of wells accessible for a nominal fee would have solved this problem. Unfortunately this was not the case in late 2013. What did exist were three databases run by two companies as JlP's whose software was did not reflect current technology and was not particularly user friendly. Further, the databases collectively held about 100,000 wells (roughly 5% of the global well stock) to cover onshore, offshore platform and subsea and well types from PCP, ESP, gas lift and natural producer and water injector.
At the time of writing this paper, the oil price was under $50/bbl, its lowest for many years, triggering an industry shake up that will question every dollar being spent on well operations and interventions. The key question that faced Tullow was, ‘what is the expected run life for ESP's so that a realistic economic forecast can be made on the work over frequency for the various fields’.
This paper discusses a two year journey to develop a global database, its outcomes and the benefits of the industry working together to provide one searchable database for the use of contributing industry stakeholders.
Incretin-Based Drugs and Adverse Pancreatic Events: Almost a Decade Later and Uncertainty Remains
Authors: Azoulay Laurent 
Published: May 2015

Over the past few years, substantial clinical data have been presented showing that incretin-based therapies are effective glucose-lowering agents. Specifically, glucagon-like peptide 1 receptor agonists demonstrate an efficacy comparable to insulin treatment with minimal hypoglycemia and have favorable effects on body weight. Thus, many of the unmet clinical needs noted from prior therapies are addressed by these agents. However, even after many years of use, many continue to raise concerns about the long-term safety of these agents and, in particular, the concern with pancreatitis. This clearly remains a complicated topic. Thus, in this issue of Diabetes Care, we continue to update our readers on this very important issue by presenting two studies evaluating incretin-based medications and risk of pancreatitis. Both have undergone significant revisions based on peer review that provided significant clarification of the data. We applaud both author groups for being extremely responsive in providing the additional data and revisions requested by the editorial team. As such, because of the critical peer review, we feel both articles achieve the high level we require for Diabetes Care and are pleased to now present them to our readers. In keeping with our aim to comprehensively evaluate this topic, we asked for additional commentaries to be prepared. In the narrative outlined below, Dr. Laurent Azoulay provides a commentary about the remaining uncertainty in this area and also discusses the results from a nationwide population-based case-control study. In the narrative preceding Dr. Azoulay’s contribution, Prof. Edwin A.M. Gale provides a commentary on the report that focuses on clinical trials of liraglutide in the treatment of diabetes. From the journal’s perspective, both of the articles on pancreatitis and incretin-based therapies reported in this issue have been well vetted, and we feel both of the commentaries are insightful.
—William T. Cefalu
Editor in Chief, Diabetes Care
Land use changes of historical structures in the agricultural landscape at the local level — Hriňová case study
Authors: Mojses Matej , Petrovič František 
Published: May 2015

AbstractThe aim of this paper is to describe agricultural landscapes in the cadastral area of Hriňova and their development in the context of social and economic changes over the past 60 years. This area is characterized by the occurrence of historical structures of agricultural landscape (HSAL) which are important because they comprise various cultural, environmental and ecological aspects. The assessment of land use changes on the two scales of cadastral area and selected small localities highlights that the most important trend here is agricultural extensification. The results show that despite these changes in land use, the historical structures in the agricultural landscape represented by forms of anthropogenic relief remain a permanent part of this research area.
Statistical evaluation of water quality parameters for two different seasons in Mahi estuary, west coast of India
Authors: Jangala Isaiah Nirmal Kumar , Sajish Poliyaparambil Ravi , Nirmal Kumar Rita , Basil George , Khan Shamiyan 
Published: May 2015

AbstractMonthly and seasonal field sampling was conducted to characterize the variations in water column nutrients along four stations in the Mahi estuary, west coast of India from July 2008 to June 2009. Water samples from five stations were studied, from which Stations 1 and 2 are contaminated with effluents released by surrounding industrial complexes. The samples were analyzed for temperature and pH insitu, and salinity, alkalinity, dissolved oxygen, BOD, sulfate, nitrite, nitrate, total nitrogen, silicate-silicon, phosphate and calcium and magnesium, as per standard methods. The results showed an increased content of sulfate, nitrate, and total nitrogen in both Stations 1 and 2. The entire data has been factorized using principal component analysis to extract total variability and linear relationships for a set of different physico-chemical parameters of the Mahi estuarine system. The results revealed that all the physico-chemical processes depend on the seasonal fluctuations in freshwater input and sea-water intrusion. Cluster analysis was carried out for station-wise average values to understand the relationships between stations. Eigen values showed that PC1 was the most significant component, representing more than 90% of the variance in water quality parameters in the Mahi estuary for both monsoon and non-monsoon seasons. The results showed high deterioration in the physico-chemical quality of water during the non- -monsoon season compared to that in the monsoon season.
Evaluation of soil resilience to anthropopressure in Łosie village (Lower Beskids Mts) – preliminary results
Authors: Nowak Agnieszka , Tokarczyk Natalia 
Published: May 2015

AbstractThis paper presents the preliminary results of research on soil resilience to anthropopressure in Łosie village (Lower Beskids Mts). The considered risks included three features which reflect soil resilience: predicted soil loss caused by water erosion, mechanical and physico-chemical filtration capacities. The average annual rate of soil loss was calculated based on the Revised Universal Soil Loss Equation (RUSLE). Analyses of mechanical and physico-chemical filtration capacities of soils were conducted on the basis of algorithms which took into account the soil texture class and groundwater table class. The results confirmed that the highest predicted soil loss takes place within arable lands, particularly those located on slopes - with up and down tillage. During the period from 1997 to 2009, predicted soil loss decreased by 57% due to the decline in the percentage of arable land in the research area. It was found that the introduction of cross-slope tillage within arable lands could decrease overall predicted soil loss up to 67%. Areas with the lowest mechanical filtration capacities were located on slopes and related to sandy clay soils whereas the areas with the lowest physico-chemical filtration capacities were situated in valley bottoms and are mainly due to the shallow level of the groundwater table. Finally, it was noted that the different types of analyzed risk do not overlap nor even do they correspond with each other, which is conditioned by different features of the environment that were taken into consideration. The obtained results have shown how important sustainable spatial planning evaluation of various types of environmental resilience is.