Atmospheric Swell Meter Model ASM-04,Measuring Units 4 head

Atmospheric Swell Meter Model ASM-04

Helps determine shale hydration or dehydration.

Investigating the swelling characteristics of shale formations is vital in selecting a proper drilling fluid to give maximum inhibition and wellbore stability. While drilling a well, a shale formation will immediately begin to swell if the drilling fluid is not completely compatible with the formation. This swelling can cause many problems, such as bit balling, pipe drag, hole sloughing, or other "gumbo" related problems. Therefore, selecting the proper drilling fluid prior to, or during the drilling operation, can be very beneficial in achieving a stable wellbore.

Problems such as stuck pipe, tight hole, washout, and sloughing can be related to shale stability. Tests used to determine if a specific shale is likely to cause problems include the capillary suction time (CST) test and the swell meter  test. CST test results show the inhibitive effects of various slats and their concentrations on the dispersion of a shale.

The Atmospheric Swell Meter (ASM) helps determine shale hydration or dehydration by measuring the increase or decrease in length over time of reconstituted or intact shale core. Together the SM and Capillary Suction Time (CST) tests determine the recommended mud system for drilling through a specific shale formation. First, a CST test is conducted to determine the correct inhibitor for the shale. Then, a variety of fluids are tested.