Thick Wall Cylinder (TWC) Test
Overview:
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Incremental costs associated with sand production remains to be a challenge for hydrocarbon producers in unconsolidated/poorly consolidated/weak intergranular cementation reservoir rock.
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The incremental costs include managing produced sand, damage to surface facilities, field equipment corrosion, reduction in productivity, and in some cases, plugging of the wellbore.
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Analytical/numerical models are available to analyze the geomechanics of sand production; the models can be verified by thick wall cylinder (TWC) collapse test, using a sample bored along the axis to replicate a wellbore/perforation cavity.
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The sample may/ may not be saturated with brine/oil (mimicking pore fluid). The sample is subjected to gradually increasing isostatic stress till the sample collapses, and the collapse strength is recorded.
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In a modified version, the experimental setup is equipped with a load cell monitoring the amount of sand being produced real time and permits detecting the onset of sanding.
Recommended Sample Dimensions:
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Length: 3” Diameter: 1.5”
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Length: 2” Diameter: 1”
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For both the sizes, the ratio between OD to ID is 3:1.