Steam Assisted Gravity Drainage Facility Research Articles

A kelly criterion based optimal scheduling of a microgrid on a steam-assisted gravity drainage (SAGD) facility

Steam Assisted Gravity Drainage (SAGD) is one of the major thermal recovery techniques to extract the Canadian bitumen. In the process, there is substantial amount of heat left behind in the reservoir at the end of SAGD operations, which can be converted to electricity and distributed profitably utilizing a microgrid. Concurrently, based on Canada’s green energy initiative, we present the integration and optimal power management of a microgrid on a SAGD facility, comprising of an Organic Rankine Cycle based turbine (ORC), a Gas Turbine (GT), a Battery Storage System (BSS), the central grid and the SAGD facility as the load. We introduce a Kelly Criterion (KC) based microgrid scheduling technique, which is based on maximizing information gain and is independent of supply-demand relationships. Based on the formulation, it was hypothesized that the KC based algorithm is superior compared to standard optimization techniques in a highly volatile electricity market. The electricity market volatility is captured via a wavelet network based forecasting technique. The case study presented highlights the advantages of the KC approach and its efficacy in a highly volatile energy market. The results show the superiority of the KC based scheduling algorithm in highly volatile energy markets, with forecast data irregularities.

Distributed Fiber-Optic Sensors Characterize Flow-Control-Device Performance

This article, written by JPT Technology Editor Judy Feder, contains highlights of paper SPE 195869, “Characterization of Flow-Control-Device Performance With Distributed Fiber-Optic Sensors,” by Ben Banack, SPE, Halliburton; Lyle H. Burke, SPE, Canadian Natural Resources; and Daniel Booy, SPE, C-FER Technologies, et al., prepared for the 2019 SPE Annual Technical Conference and Exhibition, Calgary, 30 September–2 October. The paper has not been peer reviewed. The complete paper describes piloting the collection and analysis of distributed temperature and acoustic sensing (DTS and DAS, respectively) data to characterize flow-control-device (FCD) performance and help improve understanding of steam-assisted gravity drainage (SAGD) inflow distribution. Fiber-optic-based instrumentation was deployed within FCD-equipped active wells using permanently installed coiled tubing. Logs were performed on multiple wells during stable and transient flowing conditions. Additionally, acoustic recording using flow-loop testing was completed with accelerometers, geophones, and fiber-optic cables during FCD characterization. The goal was to cross-reference the acquired acoustic signals for quantification of flow at devices and validation of performance. An overview of the flow-loop FCD acoustic characterization program is described. Introduction Installation of inflow control devices (ICDs) along SAGD production liners is common to enhance temperature conformance and accelerate depletion. Additionally, some operators advocate the installation of similar outflow control devices (OCDs) along the injection well of the SAGD well pair. Collectively, these inflow and outflow devices are often referred to as FCDs. Several FCD devices are commercially available for use in SAGD. Methodology In an effort to optimize FCD design and selection, a joint industry partnership (JIP) was formed and flow-loop testing conducted to establish FCD performance curves and erosion tolerance over wide pressure, temperature, and steam-quality ranges consistent with a typical SAGD well environment. In conjunction with flow-loop testing, several full-scale FCD deployments were completed at the JIP fields, including pilot wells at the production company’s SAGD facility. These wells were logged with fiber-optic technology. Fiber-optic-based instrumentation was deployed within FCD-equipped wells using permanently installed coiled tubing. Well-architecture-design changes to a typical completion were not required because fiber-optic sensors are used for most non-FCD wells to collect DTS data. Although DTS is a common tool for optimizing SAGD production, it has certain limitations. Specifically, temperature changes along production wells typically do not allow a detailed definition or quantification of the inflow distribution along the wellbore. In addition to DTS, DAS was performed periodically on the FCD wells. DAS logging of SAGD producers has several potential uses, including flow profiling, steam breakthrough or noncondensable gas (NCG) detection, multiphase flow characterization, electric submersible pump (ESP) performance, completion failure analysis, and 4D seismic analysis. Although FCD characterization with DAS appears promising, a knowledge gap exists regarding how to move beyond qualitative analysis to quantitative analysis of FCD performance and the lateral emulsion inflow distribution. Pending satisfactory results, DAS logging on active wells potentially can be completed to accelerate improvements of SAGD FCD performance and design as well as increase the efficiency of SAGD recovery through improved steam/oil ratio and an associated reduction in greenhouse gases.

Economic analysis of pressurized chemical looping combustion for steam assisted gravity drainage applications

A great effort is still pending in terms of thorough bottom-up economic assessments in the particular case of Chemical Looping Combustion (CLC) and Pressurized Chemical Looping Combustion (PCLC) processes. This work tries to reduce this knowledge gap through a comprehensive techno-economic analysis of PCLC technology focused on the replacement of a Once-through Steam Generator (OTSG) for the production of steam in a Steam Assisted Gravity Drainage (SAGD) facility in Alberta (Canada) by a PCLC system that burns natural gas using ilmenite as oxygen carrier.The evaluation of capital expenditure (CAPEX) for the different CLC cases analyzed revealed that the main contribution to costs stemmed from the rotating equipment. The economic performance of the CLC processes was evaluated through the Levelized Cost of Steam (LCOS) and the cost of CO2 captured. These parameters ranged between 30.45 and 39.93 CAD/t of steam (23.61–30.95 USD/t) and between 44.39 and 107.05 CAD/t of CO2 (34.41–82.98 USD/t), respectively. In the particular case of the CLC unit that operated at atmospheric pressure, the results were 34.92 CAD/t of steam (27.07 USD/t) and 75.46 CAD/t of CO2 (58.50 USD/t), which highlighted the economic benefits resulting from the use of CLC technology under pressurized conditions.Finally, comparing the economic results obtained in this framework with those found in the literature using other Carbon Capture and Storage (CCS) technologies, it can be concluded that PCLC technology has the potential to be a competitive CO2 capture option in the future for use in industrial SAGD facilities.

Energy Integration of Steam-assisted Gravity Drainage Facilities with Carbon Capture

The in-situ extraction of bitumen is one of the most energy-intensive processes and a large natural gas consumer in the Canadian oil sands industry, contributing significantly to Canada’s anthropogenic GHG emissions. In this regard, industry and technology developers are constantly looking for ways to reduce CO2 emissions from their operations through process improvements and more efficient heat production and utilisation. Post-combustion carbon capture (PCC) is one of the solutions available to achieve significant GHG reductions. This work focuses on improving the energy performance of integrated steam-assisted gravity drainage (SAGD) processes with PCC technologies. Three typical SAGD configurations have been selected, all with different water treatment and steam generation systems that are representative of active facilities, and simulated using Aspen HYSYS®. Analysis of the selected SAGD configurations revealed that significant energy savings and GHG reductions could be achieved through optimised heat recovery. The proposed retrofit projects could decrease natural gas consumption for steam generation by up to 10%. Then, several PCC technologies were considered to analyse the systems aspect when integrated into SAGD facilities, with a view to maximising the synergies between the two processes from an energy and water standpoint. The results revealed that the SAGD process configuration, the type of PCC technology, and the level of heat integration within the SAGD plant have a direct impact on the amount of CO2 that can be captured.

Ilmenite ore as an oxygen carrier for pressurized chemical looping reforming: Characterization and process simulation

Chemical looping reforming is a promising option for the conversion of gaseous fuels to high quality syngas suitable for gas-to-liquids (GtL) processes. This work evaluates the potential for syngas, heat, power, and steam generation for diluent production at steam assisted gravity drainage (SAGD) facilities using low cost ilmenite ore pressurized chemical looping reforming (PCLR). Preliminary fixed-bed reactor testing on a naturally occurring Canadian ilmenite ore was performed to determine the optimal operating regime for syngas generation. Based on SEM characterization, EDX elemental mapping, XRD, and Mössbauer spectroscopy measurements it was demonstrated that partial reduction to Fe2.5+ and Fe2+ containing species is required to avoid the production of CO2. Additionally, the reduction to Fe° containing species should be minimized to limit the formation of carbon and metal carbides. These results were used to generate material and energy balances via Aspen HYSYS V9 process simulation software of the entire PCLR process for SAGD applications using a Canada’s Oil Sands Innovation Alliance (COSIA) SAGD facility template. Thorough energy integration of the combined PCLR-SAGD process using Pinch Analysis suggests that steam and diluent requirements can be met, with excess power generation, at lower costs than more traditional syngas generation technologies, while meeting CO2 emissions targets and reducing boiler feed water (BFW) make-up. Having shown that process performance is attractive, a techno-economic assessment to establish the most economical design for the PCLR-SAGD process is now required.

Application of molten carbonate fuel cell for CO2 capture in thermal in situ oil sands facilities

The application of molten carbonate fuel cell (MCFC) technology for carbon capture at a thermal in situ oil sands facility has been studied. A steam assisted gravity drainage (SAGD) facility with once-through steam generator (OTSG) was used as a base case. Engineering modelling was conducted to compare the base case with no carbon capture, and with carbon capture from an OTSG facility using MCFC or amine-based carbon capture. The results indicate that MCFC has the potential to significantly reduce the carbon capture cost at a SAGD facility and to export low GHG intensity electric power. For a 33,000 barrels of oil per day (or 99,000 barrels of steam per day) production facility, a 76MW sized MCFC would be required to capture 90% of CO2 from the OTSG. Of the 76MW power from MCFC, approximately 48MW can be exported. If reliably produced, excess power generation may provide CO2 credits by offsetting Alberta grid electricity, possibly leading to a negative carbon footprint in bitumen production. Excess power would also provide a revenue stream to cover some of the cost of capture. The carbon capture cost of MCFC would be about 30% of that for amine-based chemical solvent process.

Achieving Sustainable, Optimal SAGD Operations

Technology Update To meet the global demand for energy, the petroleum industry has been gradually increasing its development and exploitation of unconventional heavy-oil reserves. The production of heavy oil (broadly defined as having a gravity of less than 20°API) can be profitable, but operators usually generate lower profit margins than in light-oil production because of higher extraction cost, the need for diluents, upgrading cost, and the lower market price for heavier crude oils. Consequently, heavy-oil producers have to manage their assets in a sustainable manner by using the best technology available to minimize their total cost of operation and ensure a timely return on investment. The vast majority of the world’s heavy-oil reserves are found in Canada, Venezuela, and Russia. Canada has the largest heavy-oil reserves, approximately 175 billion recoverable bbl trapped in the form of oil sands. Extraction of heavy crude from the sands requires unconventional and unique methods (Farouq Ali 2003). The two preferred production methods are open-pit mining and in-situ processes, with steam-assisted gravity drainage (SAGD) being a commonly used in-situ method. Open-pit mining can be used to extract approximately 20% of the recoverable crude from oil sands, while in-situ methods such as SAGD can be used to produce the remaining 80%. In Canada, that would represent approximately 140 billion bbl. Open-pit mining is a mature technology with a large environmental footprint, and this method can only exploit resources near the surface. On the other hand, SAGD has a much smaller footprint, even as it unlocks reserves well beyond the reach of mining operations. Thus, in areas such as the Athabasca and Cold Lake regions of Alberta, SAGD operations have been emerging and rapidly expanding. Fig. 1 is an artistic representation of an SAGD facility, including some common injection points for oilfield chemicals. In SAGD, the two most common types of chemical treatments are related to emulsion separation and water clarification for reuse of water in steam generation.

Is a Paradigm Shift in Produced Water Treatment Technology Occurring at SAGD Facilities?

Abstract Over the past few years, a paradigm shift has occurred in the treatment of produced water for steam-assisted gravity drainage (SAGD) heavy oil recovery facilities. The shift has been away from the use of warm lime softening (WLS), filtration and weak acid cation (WAC) ion exchange to pretreat de-oiled produced water to an approach using falling film, mechanical vapour compression (MVC) evaporation to produce steam generator feedwater. Today, approximately 16 such evaporators are operating, under construction or in various stages of delivery in Alberta and overseas. Many new SAGD facilities are evaluating MVC evaporation as the "baseline?? approach with the "traditional?? WLS/WAC system being treated as a secondary alternative, along with other alternative approaches. This shift in methodology is because of a combination of technical and economic factors, increased reliability and availability associated with MVC evaporation and, perhaps most significantly, because of the potential to use standard drum boilers and alternative fuels for steam generation [as opposed to the use of once-through steam generators (OTSGs) required with the traditional approach]. Requirements for increased water recovery at SAGD facilities, which are made possible by MVC evaporation, also play a significant role in the shift towards produced water evaporation. This paper presents a technical and economic evaluation of the shift towards produced water evaporation, increased water reuse and recovery, use of standard drum boilers and the use of alternate fuels at SAGD heavy oil recovery facilities. Introduction Over the past few years, water treatment and steam generation methods for heavy oil recovery processes have rapidly evolved. Traditionally, especially for cyclic steam operations, OTSGs, driven by natural gas, have been used to produce about 80% quality steam (80% vapour, 20% liquid) for injection into the well to fluidize the heavy oil. However, the relatively new heavy oil recovery method, referred to as SAGD, requires 100% quality steam for injection. To allow the continued use of OTSG for SAGD applications, a series of vapour/liquid separators is required to produce the required steam quality. For both SAGD and non-SAGD applications, pretreatment of the OTSG feedwater has consisted of silica reduction in a hot lime softener (HLS) or WLS, filtration and hardness removal by WAC ion exchange.

Technical Advancements in SAGD Evaporative Produced Water Treatment

Abstract There has been a shift away from the use of warm lime softening (WLS) and weak acid cation (WAC) ion exchange for produced water treatment to the use of mechanical vapour compression (MVC) evaporation followed by high pressure drum-type boilers. Approximately 18 steam assisted gravity drainage (SAGD) produced water evaporators are operating or are in various stages of construction in Alberta and overseas. Since the commissioning of the first such evaporators in 2002, many technical advancements have occurred which have resulted in reduced operating costs, improved reliability, reduced scaling and fouling potential, improved distillate quality and improved boiler feed quality for steam generation. This paper provides details of the technical advancements in evaporative produced water treatment based on full-scale operating data and lessons learned. It also presents improved evaporator configurations, discusses improvements in contaminant reduction and scale prevention systems, demonstrates how capital and operating costs can be drastically reduced as compared to earlier evaporator system designs, and provides recent advancements in modularization, evaporator disposal treatment, deoiling, membrane preconcentration, and zero discharge solids drying techniques. Introduction Over the past few years, there has been a rapid shift away from the use of traditional produced water treatment methods using WLS for silica reduction and WAC ion exchange for hardness removal, to the use of evaporative produced water treatment methods at SAGD facilities. With the use of evaporative produced water treatment, standard drum boilers are utilized for steam generation in lieu of once through steam generators (OTSG) and vapour liquid separators. This shift has occurred because of technical, economic and reliability factors, resulting in markedly improved life cycle costs for SAGD facilities. A simplified block flow diagram of the traditional approach to produced water treatment and steam generation is provided in Figure 1. A block flow diagram for the evaporative approach is provided in Figure 2.

Operational Data From the World's First SAGD Facilities Using Evaporators to Treat Produced Water for Boiler Feedwater

Abstract Many new Steam-Assisted Gravity Drainage (SAGD) heavy oil recovery facilities have recently shifted from the use of warm or hot lime softening, filtration and weak acid cation (WAC) ion exchange to pretreat de-oiled produced water to an approach using falling film, mechanical vapour recompression evaporation to produce steam generator feedwater. This method of SAGD-produced water treatment is much simpler to operate, is more cost effective and results in significant increases in equipment reliability, on-stream availability and, ultimately, oil production. There are currently about 14 such evaporators operating, under construction, or in various stages of delivery in Alberta and overseas. Several of these evaporators produce feedwater for standard drum-type boilers rather than the traditional Once-Through Steam Generators (OTSG) due to the high level of water purity obtainable with the evaporative approach. This paper provides data from operational facilities, including evaporator distillate quality, heat transfer information, fouling rates, cleaning frequencies, energy and chemical consumption, and other technical and operational data. In conjunction with this evaporative produced water treatment process, some facilities have taken the additional step of recovering all liquid waste streams for re-use in the plant, resulting in zero liquid discharge (ZLD). Designing the facility for ZLD eliminates the need for deep well injection, minimizes make-up water requirements and simplifies the permitting process. Introduction The recovery of heavy oil from oil sands formations requires large volumes of water; sometimes three times the amount of water compared to the oil recovered. In steam-assisted gravity drainage (SAGD) facilities, 100% quality steam is injected into the well to heat up the formation and get the heavy oil to flow. Oil and condensed steam are brought to the surface where the oil is separated and the condensate, or produced water, is treated and recycled to produce the steam. This huge water demand and ultimate conversion to steam requires the maximum amount of recycle potential from the water. Produced water derived from oil recovery processes (SAGD and non-SAGD) can be characterized as predominantly sodium chloride brine with high silica and minimal amounts of hardness. High alkalinity is present as well. Overall concentration of the water can range from about 1,000 mg per litre TDS to over 10,000 mg per litre, and there is always some amount of organic material present. The method of converting this water to boiler feedwater must be carefully evaluated, both technically and economically. This paper discusses an evaporative method of deriving high quality boiler feedwater from produced water. A comparison is made to the 'traditional' method of warm (or hot) lime softening combined with weak acid cation exchange (WLS/WAC). A complete evaluation of these two approaches must also include the steam generation equipment. Having high quality boiler feedwater, as derived from an evaporative process, allows the use of drum boilers in lieu of once-through steam generators (OTSG). Since the WLS/WAC system does not produce a high quality water, OTSG must be used as these boilers are more tolerant of poorer quality feedwater.

World's First SAGD Facility Using Evaporators, Drum Boilers, and Zero Discharge Crystallizers to Treat Produced Water

Abstract Steam assisted gravity drainage (SAGD) heavy oil recovery facilities have traditionally used a combination of warm or hot lime softening, filtration, and weak acid cation (WAC) ion exchange to pretreat de-oiled produced water. The pretreated water is directed to "once-through" steam generators (OTSG) to produce 750–80% quality steam. The steam-water mixture goes through a series of vapour-liquid separators to produce the 100% quality steam required for injection into the oil well. The steam fluidizes the heavy oil and allows the oil/water mixture to be brought to the surface. The oil is recovered as product and the produced water is de-oiled and treated for reuse in the OTSG. An alternative method of produced water treatment and steam production, which has recently been implemented in Alberta by Deer Creek Energy, is mechanical vapour recompression evaporation followed by standard drum boilers. This method of SAGD steam production is much simpler to operate, is more cost effective, and results in significant increases in equipment reliability, on-stream availability, and ultimately in increased oil production. In conjunction with this process, Deer Creek Energy has taken the additional step of recovering all liquid waste streams for reuse in the plant, resulting in zero liquid discharge (ZLD). Designing the facility for ZLD eliminates the need for deep well injection, minimizes make-up water requirements, and simplifies the permitting process. Introduction Water treatment and steam generation methods for heavy oil recovery processes have rapidly evolved over the past few years. Traditionally, once-through steam generators (OTSG) have been used to produce about 80% quality steam (80% vapour, 20% liquid) for injection into the well to fluidize the heavy oil. However, the relatively new heavy oil recovery method referred to as steam assisted gravity drainage (SAGD) requires 100% quality steam for injection. In order to allow the continued use of OTSG for SAGD applications, a series of vapour-liquid separators is required to produce the required steam quality. For both SAGD and non-SAGD applications, pretreatment of the OTSG feedwater has consisted of silica reduction in a hot or warm lime softener, filtration, and hardness removal by weak acid cation (WAC) ion exchange. In most cases, the OTSG blowdown is disposed of by deep well injection. A simplified block flow diagram of this traditional approach to produced water treatment and steam generation is provided in Figure 1. As the use of the SAGD process became increasingly common for heavy oil recovery in Alberta and worldwide, the traditional methods of produced water treatment and steam generation were re-evaluated to determine whether other alternative methods may provide more technically and economically viable solutions. This paper compares the use of traditional methods with an alternate method being implemented in Alberta the use of falling film, vertical tube vapour compression evaporation for produced water treatment, standard 100% quality drum boilers for steam production, and zero liquid discharge (ZLD) crystallizers to eliminate the need for deep well injection. Both technical and economic criteria are presented.

Effects of Chemical Application on Antifouling in Steam-Assisted Gravity Drainage Operations

The fouling behavior of water streams in steam-assisted gravity drainage (SAGD) operations can be affected by chemical selection, including a reverse emulsion breaker, demulsifier, flocculant, and dispersant. Reverse emulsion breakers and demulsifiers were chosen to give the cleanest water quality and best dehydration during laboratory testing of reverse emulsions produced at SAGD facilities. A group of polyquaternary amine reverse emulsion breakers were synthesized to have a range of molecular weights with equivalent charge densities. The effect of their molecular weights on water clarification was investigated by standard bottle testing. It was found that the higher the molecular weight, the more effective the chemical was at removing suspected fouling agents. A flocculant has to be used with care to avoid overtreatment of the system. If fouling occurs during normal operation due to produced water from the primary separation vessel containing residual amounts of oil or other impurities, remediation can be used to address the fouling. A series of dispersants were tested to check if the oil could be kinetically stabilized in the produced water phase. It was shown that decreased viscosity of the oil increased the tendency for the oil to be dispersed. Certain surfactants helped the oil to be dispersed into the water and then to be released upon settling for 30 min. This type of dispersant could be applied in any SAGD operation with heat exchanger fouling problems.