PowerPoint Presentation

Leverage Microfluidics Methods to Measure Relevant Canadian Oil Reservoir Fluid Properties

Lab-on-a chip measurement : Solubility

Soheil Talebi

Supervisor : Dr. David Sinton

Department of Mechanical and Industrial Engineering

Oil Sanda mixture of sand, water, clay and bitumen

Bitumen Bitumen is oil that is too heavy or thick to flow or be pumped without being diluted or heated

BitumenCrude Oil

The estimated worldwide deposits of oil are more than 2 trillion barrels (320billion cubic metres);[3]the estimates include deposits that have not been discovered. Proven reserves of bitumen contain approximately 100 billion barrels,[4]and 70.8%, are in Alberta, Canada.[1] Canada has most of the world's supply of natural asphalt/bitumen, covering 140,000 square kilometres[61](an area larger than England), giving it the second-largest provenoil reservesin the world.2

Steam Assisted Gravity Drainage (SAGD)An enhanced oil recovery technology for producing heavy crude oil and bitumen.

Steam Assisted Gravity Drainage(SAGD; "Sag-D") is anenhanced oil recoverytechnology for producingheavy crude oilandbitumen. It is an advanced form ofsteam stimulationin which a pair ofhorizontal wellsis drilled into theoil reservoir, one a few metres above the other. High pressure steam is continuously injected into the upperwellboreto heat the oil and reduce itsviscosity, causing the heated oil to drain into the lower wellbore, where it is pumped out. Dr. Roger Butler, engineer at Imperial Oil from 1955 to 1982, invented the steam assisted gravity drainage (SAGD) in the 1970s3

Improvement on SAGD

Geometrical improvement : related to well configuration

Chemical improvement: related to the thermal efficiency, fluid saturation and interfacial tension

- Traditional solvent injection (VAPEX)- Warm solvent injection- Warm solvent injection with condensation - Solvent SAGD

i. (VAPEX) in which solvent remains in vapour phase at reservoir conditions. Solvent vapour diffuses to the adjacent bitumen at the edge of the solvent chamber and dilutes and mobilize the bitumen.ii. Warm solvent injection in which the solvent is pre-heated. The viscosity of Athabasca bitumen reduces by a factor of 100 when it warms by 25- 30C. At elevated temperatures, diffusion of solvent is faster and bitumen flows more readily, however, solvent solubility is lower. Thus the effectiveness of this process depends on a combination of factors.iii. Warm solvent injection w/condensation in which solvent is injected in the vapour state and then condenses within the reservoir. By employing the latent heat of condensation of the solvent, this process is conceptually similar to SAGD. This mode is the first focus of the project.iv. Solvent-SAGD in which the solvent is co-injected with steam, similar to the traditional SAGD process. This mode is effectively a SAGD process with a solvent additive, and will be the secondfocus of the project.4

Why using solvent ? Reduce CO2 emissions associated with SAGD Enhance the oil recovery Extend the range of applicability to thinner reservoirs (higher permeability)

However...!lack of quantitative assessment of the pore-scale mechanisms active in this processChoice of the right solvent mixture and set of operating conditions for a given reservoir (i.e. pressure, temperature, injection flow rate, and concentration)

Therefore!Reservoir-relevant fluid properties, solubility and viscosity are also essential to inform the reservoir models operators use in decision making and assessment

Although solvent based processes offer potential financial and environmental advantages over conventional SAGD, a lack of quantitative performance assessment and a lack of relevant fluid property data are barriers to adoption. Specifically a lack of understanding in solvent/bitumen and solvent/steam/bitumen interactions and the associated pore-scale physics is a major source of uncertainty in solvent-injection and solvent-SAGD operation design and development.5

First phase:Recovery factorFront velocityEmulsion distribution

Second phase:Solubility measurement Viscosity measurement

Measurement of Oil swelling factor

Advantages:

Oil swelling can mobile some of the residual oil so that it can be recovered Oil swelling also increases oil saturation and consequently the relative permeability of oil

Motivations:Microfluidic solubility measurement High pressure High TemperatureHigh accuracySmall sampleFastOther application:Mass transfer quantificationBitumen swelling measurement Light-medium-heavy oilAsphaltene precipitation Why Microfluidic ?

Solubility Chip

Bitumen 20*20 (um)Solvent 100*250 (um)

WHMicro PVT cell250*250 (um)

Bitumen main channelSolventmain channelBitumen neckBit/solv cellL1 and V1L2 and V2L1 >> L2 ~ 10 L2: Diffusion doesnt reach the bitumen main channel.

V2 >> V1 ~ 20-25 V1: swelling factor is not affected by the bitumen in the neck.

A2 > A1: boundary condition can be applied to the bit/solv cell.Solubility Chip

L1L2

WH

L1 + L2D = 5E-10 m2/s

L1L2L2

L1L2D = 5E-9 m2/sL1 + L2L2

L1L2D = 5E-8 m2/sL1 + L2L2

Experimental setup

Solubility chip

Non-treated Surface Treated Surface (Silanized) Filling

The inner surface of the chip has been Silanized to make the surface non-wet to bitumen.The following procedure is done to proof the swelled bitumen is due to the solubility of the bitumen not because of the pressure of the propane.The chip is filled with bitumen at 65 C. The chip is maintained at this temperature for about 24 hours. There is no bitumen wall. (Figure 1, 2)

Figure 1 : t = 1 hours Figure 2 : t = 24 hours

Bitumen DirectionBitumen DirectionPropane DirectionPropane DirectionProof of concept

Nitrogen is injected into the chip (from the top) at 6, 10, and 20 bar. The effect of pressure on bitumen has been investigated. (The chip is maintained at 65 C whole time). At 6 and 10 bar there is no sign of change. At 20 bar there is some change on the meniscus and there is some back flow, however the change is completely different than the effect of swelling. (Figure 3, 4, 4)

Figure 4 : Nitrogen 10 barTime = 60 mins to 120 minsFigure 5 : Nitrogen at 20 barTime = 120 mins to 180 minsFigure 3 : Nitrogen 6 barTime = 0 to 60 mins

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Propane @ 7.2 bar Time = 0 Propane @ 7.2 bar Time = 45 minsPropane @ 7.2 bar Combined images

Top View of PVT cellIsometric View of PVT cell

Top View of PVT cellTop View of PVT cellIsometric View of PVT cell

Image analysis Curve Fitting

Swelling Factor : 1.0469

Chip cleaning

With new surface treatment the chip is 100% re-usable. The cleaning process is fast and easy (4 hours) comparing with non-treated chip which is not 100% cleanable.

Figure 6 : The chip is cleaned and is re-usable

Thanks