bluuebunny/crossref_metadata_2025_split huggingface dataset:
Modeling of Steam-Liquid Flow Inside and Around SAGD Wells During Startup Stage
Authors: Doan Q. , Doan M. , Ali S. M. 
Published: June 2012

ABSTRACT
Canada’s oil sands deposits in northern Alberta are estimated to contain more than 1.35 trillion barrels (~215 billion m3) of bitumen. Such a large resource base constitutes the world’s second largest oil reserves (behind only Saudi Arabia’s), even allowing for (relatively) low recovery factors. In-situ recovery technologies for these deposits, in view of the extremely viscous bitumen typically existing in them, commonly require thermal heating and/or solvent dilution to mobilize the bitumen and enable it to be produced. SAGD and CSS are currently two technologies accounting for the bulk of in-situ bitumen production in Canada.
The SAGD process, utilizing two long parallel horizontal wells (upper well for steam injection, lower well for production), involves typically three sequential stages: Start-Up (Circulation), (proper) SAGD, and Wind-Down (or Blow-Down). In the Start-Up stage, steam is circulated through the two horizontal wellbores for sufficient time duration to create communication between them, prior to converting to SAGD operation. During this stage, complex heat and mass transfer phenomena occur in counter-current flow in the tubing and annulus (or tubing), and between the wells and adjacent reservoir. This paper first reviews briefly the common approaches currently utilized to model the Start-Up stage for a SAGD well pair. Next, it presents simulation results of transient steam-liquid flow inside SAGD wells, and temperature changes at the inter-wells midpoint reservoir, for a case typical of Athabasca SAGD project. Discussion – based on the distribution of steam quality, pressure and temperature losses along the axial well length – is provided, as is the estimation of the duration for effective SAGD circulation for the cited example.
Optimal Design of Low Temperature Air Injection for Efficient Recovery of Heavy Oil in Deep Naturally Fractured Reservoirs: Experimental and Numerical Approach
Authors: Mayorquin-Ruiz Jose Ramon , Babadagli Tayfun 
Published: June 2012

Abstract
Low temperature air injection (LTAI) can be a possibility if injected air diffuses into matrix effectively to oxidize oil in it creating enhanced gravity drainage of lower viscosity oil. However, early breakthrough of air with partial consumption of oxygen due to the highly conductive nature of the reservoirs is a concern. Once it is controlled by proper injection scheme and consumption of air injected through efficient diffusion into matrix, LTAI can be an alternative technique for heavy-oil recovery from deep NFR.
Limited number of studies on light oils showed that this process was highly dependent on oxygen diffusion coefficient and matrix permeability. In this process, oil production is governed by drainage and stripping of light oil components has a greater effect on recovery than the swelling of oil.
In the present study, static laboratory tests were performed by immersing heavy-oil saturated porous media into air filled reactors to determine critical parameters on recovery; diffusion coefficient and gravity drainage rate. A data acquisition system was established for continuous monitoring of pressure at different temperatures. Also analyzed was the possibility of hydrocarbon gas additive to air to enhance diffusion into matrix. A numerical model of air diffusion into a single matrix was created to obtain diffusion coefficient through matching the lab results. Then, sensitivity runs were performed for different matrix properties and composition of injected gas (air and hydrocarbon).
It is imperative that enough timing is required for diffusion process before injected air filling to fracture network breakthrough. This implies that huff and puff type injection is an option as opposed to continuous injection of air. The optimal design and duration of the cycles were also tested experimentally and numerically for a single matrix case.
Impact of Non-Condensable Gas on SAGD Performance
Authors: Liu Yang , Xi Changfeng , Liu Shangqi , Liu Chunze 
Published: June 2012

Abstract
Non-Condensable Gasses (NCG) are gasses such as carbon dioxide, hydrogen sulphide, methane and nitrogen which can be present in a SAGD steam chamber but do not condense into the liquid phase to any large degree. Recent theoretical and laboratory work has shown that these gasses can enhance the thermal efficiency of SAGD without a significant reduction in productivity. There has been considerable discussion, both positive and negative, regarding the behavior of these gases in the steam chamber. Benefits to SAGD productivity have been suggested by some, while other authors have projected impacts on bitumen recovery.
This paper highlights how numerical simulation can be used as a tool to analyze the impact of NCG in SAGD through modification of K-value based on thermodynamic theory. As the simulated bitumen production rates were much less than those found in the field. It is necessary to adjust physical properties so as to make the gas more soluble, e.g. by artificially modifying the K values. The author has developed a method of modeling the effects of NCG in a steam zone using the new modified K value table. This paper will present the results of these simulations with and without modification of K-value and predict impact of NCG on SAGD performance.
Impact of the Distribution of Calcite Concretions on Performance of SAGD
Authors: Gates I. D. , Wang J. Y. , Robinson B. , Bunio G. 
Published: June 2012

Abstract
Carbonate-cemented concretions in Grand Rapids oil sand reservoirs are common with length scales up to several meters wide and high. The concretions can be found embedded in unconsolidated oil sands distributed irregularly within the formation. From a Steam-Assisted Gravity Drainage (SAGD) recovery process point of view, calcite concretions are nonproductive rock which can interfere with the growth of steam chambers. However, depending on the length scales of the spatial distribution, sizes, and shapes of the concretions, thermal dispersion can occur which can potentially enhance heat transfer within the oil sands formation. Thus, although calcite concretions are heat sinks that reduce the oil in place, they could potentially aid in steam chamber conformance. Heterogeneity of the SAGD steam chamber depends on the heterogeneity of the underlying geology. Here, the impact of spatial distributions and size of concretions on the performance of SAGD is examined. The temperature distribution (chamber growth) and steam chamber height and shape are examined. The results reveal that steam chamber growth and conformance is impacted by the presence of calcite concretions. Concretion nearer the SAGD wellpair have the largest impact since they interfere with steam chamber growth from the earliest stages of the process and the impact grows throughout the process yielding cold spots along the wellpair. This provides a means to decide length scales for placement of wellpairs to optimize chamber conformance and SAGD performance.
An Evaluation of Air Injection as a Follow-Up Process to Cyclic Steam Stimulation in a Heavy Oil Reservoir
Authors: Lei H. , Wang J. Y. , Gates I. D. 
Published: June 2012

Abstract
The majority of bitumen and extra heavy oil is produced by steam-based recovery processes yet these methods are energy intensive and emit large amounts of greenhouse gas to the atmosphere. Not only is the emissions intensity high due to steam generation, but also the water handling and treating facilities required for these recovery methods is expensive both to purchase and install but also to operate. A lot of focus of research has been on reduced steam processes, such as thermal-solvent techniques, as well as in situ combustion technologies such as Air Injection. Here, air injection is evaluated as a follow-up process to Cyclic Steam Stimulation in a deep thick heavy oil reservoir. The reservoir simulation model is obtained from a history-match to existing cyclic steam stimulation (CSS) field data. The results demonstrate that an additional 33% oil recovery is reached by using an air injection follow-up process. This gives a total recovery factor equal to about 55%. Based on incremental cumulative energy-to-oil ratio, the results suggest that air injection follow-up processes should be considered for post-CSS operations but that further improvement of the energy intensity is needed.
A New Mathematical Model for Colloidal Flow in Rocks: Accounting for Pore Geometry and Network Topology in Bimodal Media
Authors: You Z.. , Bedrikovetsky P.. 
Published: June 2012

Abstract
A new stochastic model for suspension/colloidal transport in porous media is developed accounting for the retention mechanism of size exclusion. The medium is modelled by two-pore-size network with triangular pore shape. The micro scale model is established using distribution functions and the macro scale equation system is generalised. The analytical solution is obtained for deep bed filtration of distributed particles in bimodal media. Comparison between model prediction and experimental data shows good agreement, which validates the proposed model.
Controlled Electrolytic Metallics-An Interventionless Nanostructured Platform
Authors: Salinas Bobby J. , Xu Zhiyue , Agrawal Gaurav , Richard Bennett 
Published: June 2012

Abstract
Completion devices such as fracturing balls, discs, and plugs are often used for downhole fluid and pressure control. Current polymer material must be milled away, flowed back or otherwise removed before production. Severe deformation of currently used materials that prevent flowback have been reported, requiring costly intervention operations to either remove or replace the tools and resulting in higher operational inefficiency. Using controlled electrolytic metallic (CEM) material eliminates this possibility. The new material is inherently designed for in-situ digestion in downhole environments at a controlled customizable rate.
Conventional degradable materials have a well-known tradeoff between dissolution rate and mechanical strength, which limits their utility. Increasing the dissolution rate often lowers the mechanical strength of the material below an acceptable threshold for many downhole applications. Using a reactive material with a blended nanostructured coating of ceramic and/or metallics provides the strength for initial operation and the ability to control the rate of corrosion later in the product's operation cycle. CEM materials have three times the strength of their base material and the corrosion rate can vary by a factor of several hundred, as compared to the base material. Corrosion rate could be further accelerated in HCl, thus providing operational flexibility. Experiments in various fluids and temperatures validate the corrodibility of CEM material.
This paper will present the chemistry and layering of the nanoscale coating within the grain structure, the unique material properties, and lab testing data of this truly interventionless nanostructured material technology.
CFD Investigation of Flow and Heat Transfer of Nanofluids in Isoflux Spirally Fluted Tubes
Authors: Salama Amgad , Azamatov Abdulaziz , El Amin M. F. , Sun Shuyu , Huang Huancong 
Published: June 2012

Abstract
In this work, the problem of flow and heat transfer of nanofluids in spirally fluted tubes is investigated numerically using the CFD code Fluent. The tube investigated in this work is characterized by the existence of helical ridging which is usually obtained by embossing a smooth tube. A tube of diameter of 15 mm, 1.5 mm groove depth and a single helix with pitch of 64 mm is chosen for simulation. This geometry has been chosen for simulation because it has been investigated experimentally for pure fluids and would, therefore, provide a verification framework with our CFD model. The result of our CFD investigation compares very well with the experimental work conducted on this tube geometry. Interesting patterns are highlighted and investigated including the existence of flow swirl as a result of the existence of the spirally enhanced ridges. This swirl flow enhances heat transfer characteristics of this system as reported in the literatures. This study also shows that further enhancement is achieved if small amount of nanoparticles are introduced to the fluid. These nanoparticles (metallic-based nanoparticles) when introduced to the fluid enhances its heat transfer characteristics.
Stabilizing Nano Particle Dispersions in High Salinity, High Temperature Downhole Environments
Authors: McElfresh Paul , Wood Marodi , Ector Daniel 
Published: June 2012

Abstract
Nanoparticle dispersions (NPDs) are an emerging new technology in the oil and gas industry which can be applied to EOR, well remediation, and formation damage removal to stimulate hydrocarbon production using the unique properties that colloidal particles possess. Nanoparticles have a high surface area to volume ratio allowing a greater efficiency for chemical interactions to occur. However, nanoparticle dispersions are often difficult to stabilize in harsh downhole environments. The dispersion can quickly become unstable and agglomerate when the fluid is subjected to changes in pH, or encounters increased salinity and/or temperature. Agglomeration renders the fluid ineffective, and at worst can cause severe damage to the formation. The development of highly concentrated nanoparticle dispersions stable in high TDS brine at high temperatures has been achieved and verified in the laboratory with imbibition tests and dynamic core flow experiments.
NPDs can be stabilized in the reservoir by altering charge density, hydrodynamic diameter, and the zeta potential of the particles. This is accomplished by surface modification, as well as with the addition of stabilizing chemistry.
This paper presents solutions to the destabilizing elements encountered in the reservoir, that until now have inhibited the downhole utilization of nanoparticle dispersions. Stability research of NPD fluids in brines empirically illustrates that by chemically modifying the particle surface and the surrounding aqueous environment, the fluids will remain properly dispersed and active in destabilizing bottomhole conditions. This will further pave the way for industry research into new applications of nanoparticle based fluid systems.
Nanomaterials in Fracturing Applications
Authors: Lafitte Valerie , Tustin Gary , Drochon Bruno , Parris Mike 
Published: June 2012

Abstract
Cross-linked fluids have been used in the oil industry for more than 40 years in applications such as hydraulic fracturing and water control. Today, these fluids need to be reformulated in order to respond to new challenges, such as harsher reservoir conditions and they also need to comply with tighter environmental legislation. Nanotechnology may well provide an answer to this end. By utilizing unique features such as high surface/volume ratio and specific surface functionalisation, we are able to change the nature of the cross-linking and hence better achieve the required gel properties.
This paper describes the synthesis of a series of boronic acid functionalised nanoparticles and their application to guar crosslinking. In particular, the synthesis of 15 nm boronic acid functionalized polymeric nanomaterials (also called nanolatexes), using microemulsion polymerization were investigated. Such nanodevices showed, for the first time to our knowledge, unique crosslinking properties with guar. It was found that these larger crosslinkers, as compared to standard borate molecules, can crosslink guar at much lower polymer concentrations, effectively lowering the critical overlap concentration of the polymer. We were also able to generate stronger gels over a wide range of guar concentrations. Furthermore, the optimal amount of boron required to achieve these gels was of the order 20 times lower than that with conventional borates.
This result suggested that the efficiency of the crosslinking was much higher in the case of the nanoparticles. Several rheological and stability tests were performed under field conditions and these indicate these systems have potential uses as oilfield materials. The influence of the surface chemistry of the nanoparticles was also studied along with other functionalization of other nano-materials, such as nano-silica and graphite. These results will also be presented.
Improvement of Silicate Well Treatment Method by Nanoparticle Fillers
Authors: Lakatos I.. , Lakatos-Szabó J.. , Szentes G.. , Vágó Á.. 
Published: June 2012

Abstract
The divers silicate technologies have been used more than 120 times in Hungary, Germany, Serbia and Oman for reservoir conformance improvements including water shut-off and profile correction in oil and gas wells, restriction of gas conning in oil reservoirs, blocking of gas leakage in gas storage and restriction of CO2 migration in a collapsed well. The advanced methods based on simultaneous application of polymers, urea, humates, etc. recognizing that the pure silicate gels have disadvantageous properties under reservoir conditions. The present efforts were focused on replacement of some additives in gel-forming solutions; meanwhile the efficiency of the method remained the same or even better under various formation conditions. Based on earlier results, it was proved that addition of water-soluble polymers to silicates improved significantly the stability and flexibility of such gels. Beside the beneficial effects, however, the polymer-containing silicate solutions may also have some drawbacks to placement and in-situ dispersion of treating fluids. These difficulties can be eliminated by replacing polymers with nanomaterials. The detailed laboratory studies focused on polymer free, but SiO2 and Al2O3 nanoparticle containing silicate solutions. Results of laboratory study of gelation mechanism, rheological properties, flow behavior, and nanoparticle sizing served to draw fundamental conclusions. It has been shown that these nanomaterials can replace completely the polymers, they are compatible with even low permeability porous, and fractured media, and less pH-controlling agent is necessary to catalyze gelation.
Recently, the efficient and flexible silicate technologies arouse high interest in oil and gas production. Their environment friendly solutions are particularly appreciated. Replacing the often-questionable synthetic polymers in gel-forming solutions with nanomaterials is the final step toward to use harmless chemicals in absolute sense. Based on the laboratory tests the silicate/nonmaterial method was tailored to oil producers operating in the largest Hungarian oil field. The pilot tests will be carried out in 2013. Combining silicates and nanomaterials, new and efficient method was developed for water shutoff and profile correction in various oil and gas fields and that may open new vistas in improvement of well performance of both producers and injectors.
Use of Nanomaterials in Cementing Applications
Authors: Patil Rahul , Deshpande Abhimanyu 
Published: June 2012

Abstract
The two principal functions of oilwell cementing are to restrict fluid movement between zones within the formation and to bond and support the casing. Apart from these, the cement sheath also protects casing from corroding, protects the casing from shock loads when drilling deeper, and plugs lost circulation or thief zones. Once cement is placed in the wellbore, initial setting occurs wherein development of compressive strength becomes more important for further drilling operations. Early strength development is important to help ensure structural support to the casing and hydraulic and mechanical isolation of downhole intervals. Delays in strength development cause significant amounts of lost time because of the need to wait on cement (WOC). Typically, an accelerator is often used to enable early strength development in cement. It is desired that an accelerator should improve overall compressive strength without causing excessive gelation.
Nanomaterials (being smaller in size and higher in surface area) are used in several fields, including catalysis, polymers, electronics, and biomedicals. Because of a higher surface area, these materials can also be used in oilwell cementing to accelerate the cement hydration process. Moreover, they are often required in small quantities. This paper documents a case in which nanosilica was used in cement formulations to develop high early strength. Nanosilica also helps enhance final compressive strength and helps control fluid loss. Using the correct quantity of nanosilica, it is possible to design cement slurry with low rheology and good mechanical properties while controlling fluid loss.
Synthesis and Size Control of Monodispersed Al-sulphonated Polycarboxylic Acid (Al-SPCA) Nanoparticles with Improved Squeeze Performance and Their Transport in Porous Media
Authors: Yan Chao , Kan Amy T. , Wang Wei , Wang Lu , Tomson Mason B. 
Published: June 2012

Abstract
Sulphonated polymers are used in oilfield for scale inhibition. In this study, Al-sulphonated polycarboxylic acid (SPCA) hybrid nanoparticles were prepared by an environmentally friendly approach. Particle size of these materials was controlled at about 80 nm by applying hydrothermal synthetic method with urea as slow neutralization agent. Reaction parameters such as concentration of salt solution, reaction time, urea concentration and ionic strength were investigated to optimize nanoparticle synthesis. The mobility of Al-SPCA hybrid nanoparticles decreases dramatically in 1% (w/w) KCl solution. Using phosphino-polycarboxylic acid (PPCA) as dispersant, nanoparticles were well suspended in 1% KCl solution. Absorption of PPCA to hybrid nanoparticles increases its negative surface charge and decreases particle deposition. The retention and long term flowback performance of hybrid nanoparticles were compared with the neat chemical squeeze simulation in ground core column experiments. The results showed that the slow release of sulphonated polymer from hybrid nanoparticles in porous medium leads to an enhanced squeeze treatment efficiency and successful inhibitor treatment in the oil field.
Using Nanoscale Dispersed Particles to Assist in the Retention of Polyphosphinocarboxylic Acid (PPCA) Scale Inhibitor on Rock
Authors: Ghorbani N.. , Wilson M.. , Kapur N.. , Fleming N.. , Neville A.. 
Published: June 2012

AbstractEnhancing the life of scale inhibitor squeeze treatments in the oil and gas industry is a major means of increasing productivity. Having an understanding of the route by which inhibitors such as PPCA can adsorb to the rock surface is important in designing new squeeze methodologies. Nanotechnology is emerging as an enabling technology in many fields including medicine, transport and pharmaceutical. Thus far there has been research activity in novel uses of nanotechnology in the oil and gas sector but there is still enormous potential for it to be further exploited. In the squeeze process, where fluids are pushed through the rock pore space, there is potential for nanotechnology to enhance the delivery of species (i.e. placement) and/or to assist in the "binding" of active species to the rock surfaces. It is in this area the current work is focused. In this paper we investigate the adsorption of PPCA (a common scale inhibitor) onto a C-based nanoparticle (CBN). The adsorption of PPCA on the CBN is quantified as a function of time and the concentration of the CBN. Experimental data from Inductively Coupled Plasma (ICP) illustrates a substantial adsorption of PPCA on CBNs comparing to the adsorption of PPCA on the rock. Various concentration ratios of CBNs and PPCA have been tested in dynamic adsorption tests to understand the effects of absorbent and absorbate concentration. The mass of adsorbent was assumed to be key factor in adsorption of PPCA on CBNs; indicative of the number of active sites on the nanoparticle.