Research and Development Technical Section

Dear Reservoir Community,

I am looking for some case studies where hot water is being used for injection. Theoretically simulation studies have established that in heavy oil fields where pay thickness is generally less than 5-6 m  and also in  dirty heavy oil sands, hot waterflood give better project economics.

I did some technical scouting but could not find any live heavy oil project where hot water is used as injectant to recover heavy oil.

I appreciate your comments, case study and technical inputs.

Thank & regards

R P Badoni

Development manager GPOC

South Sudan

Liquid water is a very poor heat carrier.  This is the reason industry went to the use of steam to provide heating to heavy oil reservoirs (hot water had been tried first, e.g., Kern River Field).  The heat of vaporization of water makes the use of steam much more efficient in transmitting heat to the reservoir.  Unfortunately, your reservoir thickness falls significantly below generally accepted minimums for steam projects unless you are looking at multiple closely stacked pays.  The heat losses to the over and underburden would be excessive.  You will still face significant heat losses using hot water, and volumetrically many more barrels of hot water will need to be injected to account for these losses than would be required if it were injected in the form of steam.

Your question did not note the depth of your reservoir nor how much change in temperature is required to reach your desired oil viscosity.  If the reservoir is very shallow, and not much delta temperature is desired, you might do some further research.  However, remember that as the hot water cools to reservoir temperature at the front, it will still be advancing - at a more adverse mobility ratio than if it were still hot.  Thus, fingering will become a more significant problem than one would first think considering the hot water temperature.  If you are basing your current interest in hot water based on reservoir simulation, was the reservoir model sufficiently heterogeneous and finely gridded to reasonably try and capture fingering??

Depending on how viscous your oil is, you might also consider operating a normal waterflood, accepting that you will operate for a long period at high water-oil ratios (if my memory is correct, M Kumar wrote a review paper on viscous waterfloods - ck SPE papers), or consider polymer flooding.

HI Rajendra

This a point that I have in mind for a long time. As some answers done here and at reservoir group, I agree that hot water injection may show low or even null gain as a thermal EOR technique. But water injection in a heavy oil reservoir may be not so easy, mainly if you are injecting at the oil zone. The oil saturation near injector falls very slow and then the injectivity increases slowly also. If you are limited by pressure (due to geomechanics or operational conditions), it means that you will have a strong limitation in the flowrate for some time (months or years).

In this case, hot water injection may induce a higher injectivity by an easier oil flow near the injector and then higher injection rate that should result in a better oil rate. You may check this effect by simulation refining the cells around injectors. I never checked in a real situation.

Good luck