hi, so first of do you want them to be oil wet or water we? Of course in either ways you'll need to make a saline solution and leave the samples there. The aging time might differ from 1 day to weeks and months, depends on your experiment goals, later You'l have to leave them in your oil and let a natural replacement to take place , again this can vary from 1 day to months, It's also suggested to increase the process you can use a heater (i temperature).

That's pretty much it. I used samples that were 2 months aged before.

I read an extensive paper somewhere on the topic, I will try to find it, should be somewhere in my old references. If I find it I will send i to you,

Farida Amrouche here are the papers :

1. Anderson, W.G., 1986a. Wettability literature survey – part 1: rock/oil/brine interactions and the effects of core handling on wettability. Journal of Petroleum Science and Engineering: 1125-1144.

2. Anderson, W.G., 1986b. Wettability literature survey – part 2: wettability measurement. Journal of Petroleum Science and Engineering: 1246– 1262.) .

3. Roehl, P.O. and Choquette, P.W., Carbonate Petroleum Reservoirs, New York, Springer-Verlag (1985).

I aged my samples at 80 Celsius for 5 days in each of brine and oil.

Basically aging is altering your porous media wettability.

You can refer to this paper:

https://doi.org/10.2118/62507-PA

They did the aging study on the sandstone.

If you are interested in other lithology, I just did a literature review for my paper.

Article Isolated mechanism study on in situ CO 2 EOR

You can start form there.

You need to do aging at reservoir conditions (pressure and temperature) for 42 days (1000 hours). If aging takes place in a core holder, it is recommended to flush the core with 2.5-3 PVs of fresh oil every week to replace the old oil (dynamic aging). Any change in pressure difference (delta P) across the core during the oil flushing process gives indication of permeability change.

REFERENCE:

Anderson, W. G. (1986, October 1). Wettability Literature Survey- Part 1: Rock/Oil/Brine Interactions and the Effects of Core Handling on Wettability. Society of Petroleum Engineers. doi:10.2118/13932-PA

Hi Mohammed,

Thanks for sharing. But what I`m looking for is the chemicals used (oil & base/Acid).

Kind regards

Farida

Dear.

Firstly, you need age your cores at least 24 hours with brine preferably using manual saturation at your desired experimental conditions (temp and pressure). Thereafter, you install in the coreflood equipment and flush with several PVs of brine (minimum of > 2 PV) at constant desired flow rate and monitor the differential pressure. At this stage you need to flush with PVs of oil (dead or live) at the same flow rate and as well monitor the dp until no water production. You may allow it for 48 hours aging...later inject more pvs of oil again and age (dynamic) it for another 24 hours. The dp behavior could give indication of K changes. I hope this helps...

There are a lot of different aging procedures in the literature.

This is a complex issue. A reservoir oil (live or crude) contians millions of different components, some of which will be involved in altering wettability (Resins and/or Asphaltenes). Preferably, you will have a live/crude oil sample with innate acid/base components within it's Resin and/or Asphaltene content. If you don't have crude oil then you will require an oil with added resins and/or asphaltenes.

However, common wetting components may be: acids - carboxylic acids, phenols, suphides, thiophenes; bases - amides, pyridines, quinolines, carbazoles.

Since this is complex, experimental design is important, thus it really depends what your objectives are, which requires knowledge of the mineralogy and water/salt content.

Hi all,

My question is do-decane enough to age sandstone?

Kind regards,

Farida

Dodecane - not normally, no.

Dodecane is a saturate (alkane/paraffin), a pure hydrocarbon having no polar functional groups. It will not alter wettability away from the original rock wetting. However, if the rock composition has organic material (coal, bitumen, pyrobitumen, etc) as part of it's matrix structure, then any oil may be enough for ageing - and the rock may exhibit non-water wet behaviour without ageing (may depend on initial water saturation).

Simple, available carboxylic acids that may alter wetting would be:

- Lauric acid (alternate name - dodecanoic acid) if you want something similar carbon length to dodecane.

- Palmitic acid (palm oil - hexdecanoic acid)

However, these are acidic (negative) polar components and, dependent on the rock composition, you may require basic (positive) polar components. Do you know the mineralogy of the rock?

Farida,

Aging in brine to reach water-rock equilibria (inorganic) takes a few days to weeks depending on temperature (in general). The next step is to add oil. Your model oil will not alter wettability as Jules has mentioned. I am attaching a dissertation that is relevant concerning what to add to your model oil to effect wettability. As you will see at extremely low TDS your non-polar dodecane will have some degree of wetting, but at any realistic TDS there is no wetting by the organic. Lastly, remember wet with brine first and then oil to best emulate the natural system.