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Title: Full-scale borehole sealing test in anhydrite under simulated downhole conditions. Volume 2

Technical Report ·
OSTI ID:5734517

The large bench-scale permeability testing of anhydrite rock and a grout designed to act as a seal in contact with this rock was conducted at the Terra Tek, Inc. research facility in Salt Lake City, Utah. Pressurized flow of a dye-marked fluid from the borehole cavity of the test specimen was recorded at 45 psi (0.31 MPa) differential head pressure. Test parameters were altered and the flow recorded for differential pressures varying up to about 125 psi (0.86 MPa) in 25 psi (0.17 MPa) intervals with a constant confining pressure. In all cases, the fluid flow was observed to increase. The dimensions of the test specimen and test conditions correspond to an observed permeability of between 0.84 and 1.5 millidarcys, based upon the grout plug area. Post-test examination of the rock/grout core indicated that the flow was principally interfacial flow. However, marked flow paths within the grout were also noted. The development of numerous heavily dye-marked ''washout'' regions in the grout at the interface suggests that these channels acted as the main conduits for fluid flow from the borehole. A tentative explanation for the development of the large conduits was the formation of bubble trains in the paste. Similar behavior was observed in a laboratory-scale grout formulation at the Pennsylvania State University that approximated the rheologic properties and composition of the tested grout, TT84A. The performance of the melamine-based superplasticizer used in the formulation is questioned regarding its sealing ability in anhydrite.

Research Organization:
Pennsylvania State Univ., University Park (USA). Materials Research Lab.
DOE Contract Number:
AC02-83CH10140
OSTI ID:
5734517
Report Number(s):
BMI/ONWI-581(2); ON: DE86012074
Resource Relation:
Other Information: Portions of this document are illegible in microfiche products. Original copy available until stock is exhausted
Country of Publication:
United States
Language:
English