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Slotted liner or Screen completion option
15 May 2013
What tests and analysis are necessary to perform on a core sample in lab to determine whether to run a Slotted liner or a Sand Screen for completion?
2 answer(s)
Philmccurdy
Geomechanics Engineer
Myspread Users
Total Posts: 1
Join Date: 15/05/13
Andi

You will need to know the grain size distribution to initiate selection of optimum sand control selection. There are fairly well established  industry "guidelines" based on the range of sand grain sizes and the amount of smaller"fine sized" grains but they are just guidelines and each case should be considered more specifically. Slotted liners tend to be best suited to coarse grained sands that are all about the same grain size. They may also be employed to keep the "flow conduit" open whilst accepting some sand production to surface as is common in heavy oil applications. Wide cut Slotted liners or even  drilled liners may also be used as less expenive (and not as easily plugged by mud filter cake) insurance in stronger rock formations and long horizontal wells.

Generally aside from cost or mechanical loading metal mesh sand screens are more widely applicable than slotted liners for sand control purposes.

Once you know the grain size you would ideally want to know how well the planned aperture size and type (slotted liner, wire wrap or metal mesh screen) would work by doing a "sand retetnion test". A good startig point for slot or aperture size is the D10 (i.e. the size at which 10 % of grains are that size or larger).  

Of course grain size is just one aspect and risk of shales and formation damage and required well functionality will also play in role in completion choice.

A decent, free and instantly available starting point on sand control selection is the SPE distinguished lecture linked below.

http://www.spe.org/dl/docs/2008/Ott.pdf

This poster has a decision tree but I'm not sure if any of them land on slotted liner

http://www.offshore-mag.com/content/dam/etc/medialib/platform-7/offshore/maps-and_posters/1101Sandfa...

Depending on where you are (Houston) there should be a numerous lab options nearby (e.g. corelab , corex, constein, weatherford labs, OMNI (now weatherford,) that offer grain size analysis and retention tests. The larger service co's also offer this service but for obvious reasons only test their own equipment. Mud clean up tests can also be considered (and shale stability if appropriate) which will tie in the well contruction to the completion performace.

Other references worth considering for night time reading would be
SPE 39437, SPE 88493 , SPE 85504 , SPE 114781, 158922

Hope this helps

Phil

Gordonholm
Operations Geologist
Tullow Oil Plc
Total Posts: 8
Join Date: 17/04/13
You require to do a PSD.  Particle Size Distribution. This can be done by disagregating the sample (better than crushing)and then using screens or laser.

Beware of a fines tail.  This is often caused by the presence of interstitial clays which can be interpreted as fine sand.

Cheers
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