What do you call Heavy Oil? Usually people define HO function of a viscosity threshold which is strongly but not strictly correlated to viscosity; downhole viscosity is the real discriminator for HO in-situ recovery processes - reservoir temperature is a key element, it is one of the key technical element that determine that the Orinoco belt is today a "cold" province and Athabasca a thermal one. I exclude mining, altogether another issue. Function of the viscosity threshold you will get two answers. With a low viscosity definition the answer is "solution gas drive". With a high cutoff the answer is "thermal method". Amalgamating the two is truly mixing apple and oranges. I would place the boundary around a few 10 000 Cp. CHOPS, polymer (including ASP), hot water are not contenders today for universality but competitors in the lower viscosity domain. I doubt CHOPS will be "universal", upon maturing polymer floood might get there. Variants of SAGD and CSS are contenders for pure version of those processes in the high viscosity domain but immature today.

Dear Alex, I don´t know, but let me participate to learn.

Hanno, I try to upload my Review Paper, but something wrong with the system. I will try to deliver the file by email.

Dear ROZ, BARBARA !  Thanks for your opinion toward my work. At the moment of writing this Paper in 2011, I had 50 years of professional Experience in Physicochemical Hydrodynamics, 25 years in application to Heavy Oil Recovery. I am a mere man, without any special talents, but my Major bails me out.

Dear Alexander,

If I use my common sense, being layman, two common most universal methods used, may be:

1. Search and Identify the oil wells in deep earth and slopes/flow of oil

2. Extraction by drilling from deep earth/oil wells

@Subhash. Your points are correct, but they are common for all methods.

Dear Prof. Alexander

I am not an expert of the field. However I am sharing whatever I could gather through web-browsing.

Steam-assisted gravity drainage (SAGD) is a thermal in situ recovery method that involves drilling two horizontal wells, one above the other. Steam is continuously injected through the upper wellbore, softening bitumen so that it drains into the lower wellbore and is pumped to the surface. Pairs of parallel horizontal wells, one for steam and one for production, make it possible to recover bitumen continuously from oil sands. Cyclic steam stimulation, also a thermal in situ recovery method, is a three-stage process involving several weeks of steam injection, followed by several weeks of "soaking," followed by a production phase where the oil is produced by the same wells in which the steam was injected. As production declines, the injection phase is restarted. The high-pressure steam not only makes the oil more mobile, but also creates cracks and channels through which the oil can flow to the wellbore. Attached threads may provide further information

Thanks, Yogesh, for your discussion and files attached.

You give the answer in your question : EVERY case is different and has to be evaluated on it's own merits.

At a prospect I am working on, we hope to produce successfully by a combination of absolutely conventional drilling at high angles (in increase flow area) combined with appropriate injection of surfactants in the flow stream to keep fluid viscosity down.  May have enough gas to re-inject for gas lift too. We have to keep eyes open to all options, but with very limited information and no PVT samples, we're very limited on information.

External factors are relevant too. If we ever for one second breathed the words "hydraulic fracturing", then we would never be allowed to drill the prospect. And the recent changes in oil price are making finance a much more dubious question.

Dear Prof. Alexander J. Babchin ; Here are few links may be useful to you Sir. Regards

http://scholar.google.co.in/scholar_url?url=http://www.google.com/patents/US4160479&hl=en&sa=X&scisig=AAGBfm07ox3ExBeBYHUP0E76FDrjb0xDrw&nossl=1&oi=scholarr&ei=TA3_VOn_LMqgugSA74HQDQ&ved=0CBsQgAMoADAA

http://scholar.google.co.in/scholar_url?url=http://www.google.com/patents/US6733636&hl=en&sa=X&scisig=AAGBfm3z-kusi3kW71JNNhsnfZ_VwnDgww&nossl=1&oi=scholarr&ei=TA3_VOn_LMqgugSA74HQDQ&ved=0CBwQgAMoATAA

http://scholar.google.co.in/scholar_url?url=http://www.google.com/patents/US3127935&hl=en&sa=X&scisig=AAGBfm06CFZUWo5OuYAJmcmUrZEEOBoU0A&nossl=1&oi=scholarr&ei=TA3_VOn_LMqgugSA74HQDQ&ved=0CB0QgAMoAjAA

I tried to reduce viscosity of Athabaska Bitumen by Surfactants, but found no effect.

Paul R. Yarnold: Re Ozonix etc : I'm the prospect geologist. I'll ask our production/ process guy if he knows of this material, but since we don't know if we have (or if anyone will ever get) permission to drill the prospect and no samples exist from the previous drilling, we're in an information-free zone. We (nobody) knows what was tried in the 1980s and didn't work then.

EDIT : paper title is "Gas Production Yielded by using the Patented Ecosphere Ozonix® Technology Versus Chemical Biocide for the Hydraulic Fracturing of Natural Gas Wells"

(1) The original question was about heavy oil, and our prospect is a fairly heavy (though conventional) oil ; this paper is about gas wells and biocides for fracking. We're not intending to drill a gas well, and we explicitly do not see any need for hydraulic fracturing of the formations on our prospect.

(2) Any mention of hydraulic fracturing is likely to have the prospect completely shut down by the present or future governments, either side of the next Independence effort.

I don't see any need to pursue this further. To be concerned about choice of biocide you'd need to have experienced problems on several wells on your field, and be looking for a solution. We're looking at a prospect with no wells un-plugged in 30+ years.

[Second Edit]

Before throwing the cited e-paper in the e-bin, I read a few paragraphs and got as far as "novel Advanced Oxidation Process (AOP) using Ozone, Hydrodynamic and Acoustic Cavitation, and Electro-­Oxidation, which is named the Ecosphere Ozonix process (Ozonix)"

The excessive use of Capitalisation Is a Pretty Good sign of Snake Oil dressed up as Something Worth Paying for. Now, you can call me a cynic, but I've forgotten more chemistry than most people (Dad being an industrial chemist - and this being a major reason that I'm not a chemist), and that description has my Bullshit Detector (copyrighted by The Crass in 1982) firing off. They bubble ozone into water under high pressure then call it something other than a biocide. Whoopee dee! That is so going to form a biocidally active mixture of ozone and water that I can't see any reason for not calling it a biocide, apart from the marketing manager not liking the "it kills things" meaning of "-cide".

Anywhere that the marketing people are in charge is a good place to not go near.

What do you call Heavy Oil? Usually people define HO function of a viscosity threshold which is strongly but not strictly correlated to viscosity; downhole viscosity is the real discriminator for HO in-situ recovery processes - reservoir temperature is a key element, it is one of the key technical element that determine that the Orinoco belt is today a "cold" province and Athabasca a thermal one. I exclude mining, altogether another issue. Function of the viscosity threshold you will get two answers. With a low viscosity definition the answer is "solution gas drive". With a high cutoff the answer is "thermal method". Amalgamating the two is truly mixing apple and oranges. I would place the boundary around a few 10 000 Cp. CHOPS, polymer (including ASP), hot water are not contenders today for universality but competitors in the lower viscosity domain. I doubt CHOPS will be "universal", upon maturing polymer floood might get there. Variants of SAGD and CSS are contenders for pure version of those processes in the high viscosity domain but immature today.

CHOPS does not give more than 10 % of OOIP Recovery. The best thermal agent is steam, but methods are different, depend on local reservoir conditions. 

Here, I finally succeeded in attachment of the review areicle right below the question.

I suggest cyclic steam injection or hot water flooding for cracking heavy oil molecules

Mohammed, steam based methods are effective, they lower oil viscosity, but don't crack molecules. 

The major approach to recover heavy oil is to reduce its viscosity and increase its mobility by adding thermal energy and/or chemicals.