Skip to main content

In-situ produced nanoparticles for enhanced oil recovery

Periodic Reporting for period 3 - iNanoEOR (In-situ produced nanoparticles for enhanced oil recovery)

Reporting period: 2018-08-01 to 2020-01-31

The global demand of energy is expected to increase as much as 50% in the next 20 years and the demand for oil and gas will also increase. The era of finding “easy oil” is coming to an end, and future supply will become more reliant on fossil fuels produced from non-conventional reservoirs and from enhanced oil recovery (EOR) process. Oil and gas are contained in rocks, i.e. porous media connected with different pores linked through pore-throats, and are generally produced in three stages: primary, secondary, and tertiary. For every barrel of oil we used today, there are still two barrels in the existing reservoir trapped in reservoir rocks. The development of new technologies for EOR from a particular well becomes increasingly important.
Nanotechnology may provide an alternative solution, where the fundamental question is about nanoparticles (NPs): their functionality and mobility control in the complex reservoir condition. Comparing the exiting EOR technologies, injecting NPs together with flooding fluids could have many advantages, and can be used as ‘contrast’ to provide better reservoir characterisation, for controlled delivery of chemicals, and for conformance control to increase the oil recovery rate. This project proposes a revolutionary idea: in-situ production of NPs inside the reservoir for enhanced oil recovery, termed as iNanoEOR. Rather than pre-manufacturing and stabilizing NPs in advance, which will encounter serious problems of flowing through the reservoir, NPs will be produced inside the reservoir by controlled reactions. NPs can be used as sensors to improve reservoir characterisation. Comparing with the current concept, iNanoEOR have many distinctive advantages, and could bring significant impact to the science, technology and the society.
The aim of this project is to develop and validate an innovative concept by in-situ producing nanomaterials under reservoir-like conditions, and examining the effect of nanomaterials on oil recovery by both numerical and experimental means. Four working packages are arranged to achieve this goal, including WP1 – nanoparticle fabrication and characterisation, WP2- exploring oil removal mechanisms by nanoparticles, WP3-nanoparticle mobility study and WP4-synergies and planning for field study.

The work conducted in this period are on WP1, WP2 and WP3 with a main focus on WP1. The work has been going very well according to the plan. Briefly, different nanomaterials production methods have been studied, and a range of nanomaterials were produced and characterised; rheological, interfacial and morphology properties were obtained, and three flooding systems were established including pore scale, mesoscale and core scale setup. These work has resulted in 9 journal papers published during this period, as detailed in the Publication section. These publications represent the novel production and stabilisation of nanomaterials under reservoir-like conditions, identification of oil recovery mechanisms, and the mobility of nanoparticles through different core samples.

In particular, we examined the effect of pure nanoparticles effect on oil recovery, which was found to not as strong as many prior studies. The nanoparticle effect should be more important in other aspects such as using as sensors and delivery agency. Consequently we focused our work along these two fronts, which include i) in-situ production of carbon quantum dots, and used it as sensors for oil saturation detection (the experiments have been completed and draft paper was under review) ; and ii) in-situ production of metallic oxide nanoparticles for stabilization of emulsions; and iii) learning from the success of controlled drug delivery in nanomedicine, we developed a novel concept of using nanoparticles for controlled chemical delivery to increase oil recovery. The packed column experiments showed impressive results to reduce chemical usage and increase oil recovery. The validation of these two novel concepts in packed columns, i.e. in-situ production of nanoparticles, and ii) controlled delivery of chemicals, represent the most important results of this period.
The project is highly innovative with many aspects that go beyond the the state-of-art, and the major ones include:
1) Comparing all prior work of using pre-fabricated nanoparticles for enhanced oil, nanoparitcles are produced inside the reservoir by controlled reactions. Laboratory experiments have proved that certain nanoparticles can be produced in reservoir conditions, and used as sensors to detect oil saturation, or as for stabilizing emulsions. This represent a major advancement of state-of-art
2) In addition, based on our findings that nanoparticles along may not be sufficient for enhanced oil recovery, we borrowed the concept of controlled drug delivery in nanomedicine. We use nanoparticles or nanodroplets as carriers for surfactants that used in tertiary recovery. We proved in the laboratory that using nanodroplets as carriers, the surfactant usage can be largely reduced but with improved oil recovery. This represents another big advancement. More challenging than nanomedicine application, where the pressure and temperature are low during the applications, the controlled delivery for enhanced oil recovery is more demanding considering the porous nature of the rock, the high pressure, high temperature and high salinity harsh environment in the reservoir.
3) Furthermore, we advanced mechanistic understanding of the effects of nanoparticles on interfacial / wettablibity / mobility control, from both microscopic study (molecular simulations) to pore/core scale experimental work.

Further work will investigate further these three areas, bringing current low pressure and low temperature study to HPHT conditions, and proving that the concepts are also feasible under reservoir-like conditions.

It is expected that at the end of the project, the two most important advancement of the state-of-art will be validated under reservoir-like conditions, i) in-situ production of nanoparticles for enhancing oil recovery, and ii) controlled delivery of chemicals (surfactant, polymers etc) by using nanoparticles (or in-situ produced nanoparticles) for enhanced oil recovery.