In-situ remediation of naturally occurring radioactive materials with high-permeability hydraulic fracturing

Due to the character of the original source materials and the nature of batch digitization, quality control issues may be present in this document. Please report any quality issues you encounter to digital@library.tamu.edu, referencing the URI of the item.Includes bibliographical references: p.53-54.Issued also on microfiche from Lange Micrographics.This thesis addresses the problem of removal of Naturally Occurring Radioactive Materials, NORM, and describes an effective alternative to the current treatment method for their removal. High-pen-meability fracturing, recently established in the petroleum industry, is the recommended technique. NORM are found throughout subterranean formations. Whenever fluids from petroleum or water reservoirs are produced NORM are present in varying quantities. NORM can only be sensed with radiation detectors. However, they have proven carcinogens, and the US Environmental Protection Agency has set a limit on the maximum contaminated level of any stream. Until now, the preferred method of treatment was to remove NORM from contaminated waters with specially designed filters, which in turn create a new problem. The same filters that are used to treat the water themselves become highly radioactive with a considerable disposal problem. In the petroleum industry, NORM become concentrated in the scale that is deposited inside the well or surface pipes. When scale is removed, it can be so radioactive that it can only be stored in toxic sites. Additionally, as water is produced along with oil, so are NORM. Until now, for the Gulf of Mexico at least, produced water has been released into the ocean, but the Environmental Protection Agency (EPA) is threatening to change this. In the North Sea the regulations are already stricter. There is then a compelling motivation to remove NORM before they are produced, and thus, eliminate the disposal problem. A high-permeability fracture design is presented which modifies existing petroleum practices by introducing within the proppant pack highly selective radionuclide sorbents. These sorbents, at calculated concentrations, can remove NORM readily for several years from typical flow rates containing typical NORM concentrations