Laboratory analyses were performed on cores taken from Mitchell Energy Corporation (MEC) Muse-Duke Well #1, located in Cotton Valley Lime Formation, Limestone County, Texas, to determine fracturing fluid interaction with the host rock. Laboratory analyses were performed on cores taken from Mitchell Energy Corporation (MEC) Muse-Duke Well #1, located in Cotton Valley Lime Formation, Limestone County, Texas, to determine fracturing fluid interaction with the host rock. All tests were conducted at simulated in situ conditions of 8800 psi confining pressure, 6400 pore pressure 40% saturation and 285?F. Three candidate fracturing fluids were evaluated: Versagell (Halliburton,1074 ); stratafrac 400 (Dowell,1074 ); Polaris 60 (Western). Tests were carried out to assess, (1) fracturing fluid damage to the rock permeability and (2) clean-up efforts required to return the host rock to its initial permeability. Irrespective of the initial, untreated permeability; post treatment permeability was in the tenths of microdarcies range. Initia1 permeability of the rock treated with Versage11 and Stratafrac 400 was recovered in less than 2 hours. With Polaris 60, post fracture permeability appeared to stabilize at 60 percent of the initial permeability. Further fracturing fluid/rock interaction tests will be performed with the ,above mentioned fracturing fluids on core samples from the same well and microscopic examination of the cores will also be done.