New technologies are being developed by Los Alamos National Laboratory in this project for imaging conductive reservoir fractures through precise measurements of microearthquakes at hundreds of meters from the stimulation well. To make the technology cost-effective and within the reach of a large number of independent operators, new borehole receivers have been developed for deployment within existing production tubing, or very small diameter boreholes (1 or 2 inches in diameter at total depth). Technologies developed in this project for precise location of earthquakes will provide a low-cost method for mapping reservoir fractures that will find applications in enhancing production in a wide variety of low-permeability oil and gas reservoirs. A new method developed by Los Alamos called ?Master Event Location Method,? has improved event location resolution by greater than a factor of 5. The fracture geometry provided by the new technology will help in optimizing the number and location of wells for effective drainage and in optimizing the fracture treatment. Participation in hydraulic fracture experiments conducted by a consortia of oil and gas producers and service companies engaged in production from fractured reservoirs, many informal discussions with producers, and several presentations in leading technical society meetings helped in transfer of technology to major and independent producers. Information on poorly understood aspects of the fracturing process will have a major impact on future development of tight oil and gas reservoirs, the domestic resource base of which is estimated to be 10.6 billion barrels of oil and 341 Tcf of gas. These undeveloped reserves could ultimately generate 152 and 58 billion dollars in royalty and tax incomes respectively. Los Alamos was awarded a patent for development of a borehole source for crosswell seismic work that started as a concept in this project and later funded for development by another project.