WIPP (Waste Isolation Pilot Plant) horizon free field fluid transport characteristics

Abstract

Test region pressure history measured during the May 20, 1986 DPD02 gas flow test. Test region pressure history measured during the January 20. 1987 DPD02 gas flow test. Test region pressure measured during the May 20. 1986 DPH01 gas flow test. Guard region pressure measured during the May 20. 1986 DPH01 gas flow test. Test region temperature measured during the May 20, 1986 DPH01 gas flow test. Test region pressure measured during the DPH01 brine flow test initiated on May 22. 1986. Guard region pressure measured during the DPH01 brine flow test initiated on May 22. 1986. IV

Changes in rock salt permeability due to nearby excavation

“…The interpreted formation pressures and permeabilities which bound the response of the gas-filled test intervals prior to the mine-by are 3.0 to 3.6 MPa and 2xl0~^° to 3xl0~^^ m^, respectively. The range of the interpreted permeabilities is consistent with other measurements for undisturbed rock salt (e.g., Peterson et al, 1987). The pre-excavation response shows that gas does not flow from the test intervals out into the formation, indicating that the effective gas permeability of the formation prior to excavation is zero.…”

“…The magnitude of the formation pore pressure interpreted from the pressure buildup (about 3 MPa) is less than the probable pore pressure of the undisturbed formation (about 10 MPa, Peterson et al, 1987). This indicates that the test intervals were located close enough to Room Ll (8 m) to be in a region of depressed pore pressure, or this halite layer had an anomalously low pore pressure.…”

Resource Conservation and Recovery Act: Part B permit application. Volume 8, Revision 5

“…This is 18 the first instance in which the site investigations were directly influenced by discovery of 19 deformation in the Castile and the lower Salado. 20 21 The present site for the WIPP was selected and initially investigated in 1976 to determine if the 22 desired characteristics for the preliminary site selection were present (Griswold, 1977;Powers et 23 al.,1978). As the general criteria appeared to be met during this phase, the site and surrounding 24 areas were characterized much more extensively and intensively beginning in 1977.…”

“…The potential for gravity foundering exists over most 18 of the basin, yet only a small part actually manifests such deformation. A special condition, such 19 as a localized higher water content or an anomalous distribution of water, is hypothesized to 20 explain why deformation is localized despite the pervasive density inversion (Borns et al, 1983). 21 The presence of pressur.zed brine and gas associated with some of these structures is at least 22 consistent with this explanation.…”

“…The modern distribution is caused by dissolution of the 18 Rustler halite to the west and progressing toward the east. As shown by Holt and Powers (1988), 19 sedimentary features and textures within WIPP shafts and cores that led them to propose an 20 explicit model of depositional facies for the mudstone-halite units; halite was dissolved 21 syndepositionally from mud-flat facies, especially to the west, and was redeposited in a halite pan 22 to the east. The Culebra transmissivity shows about six orders of magnitude variation across the 23 area around the site, and the changes have commonly been attributed to post-depositional 24 dissolution of the Rustler halite.…”