PTTC Survey of GasGun™ Customers

The GasGun’s first major introduction to Kansas operators was at March 2002 Technology Fair, in Wichita, conducted by the North Midcontinent region of the Petroleum Technology Transfer Council. At this meeting, and again at the Independents Day SPE/DOE Improved Oil Recovery Conference in Tulsa a few weeks later, J Integral personnel made presentations describing the technology and its applicability in the Midcontinent. The response from the Kansas industry following these meeting was overwhelming.

In early 2003, the North Midcontinent region of the PTTC conducted a survey of all the operators who had used the GasGun™. Although the response was disappointing (only 15 operators responded), the data was sufficient to project an overview of the performance of the application in Kansas. Operators shared their satisfactions and dissatisfactions with the GasGun™. A summary of this reported information is included in Table A.

In the majority of cases reported, the tool was successful in one or more of the following: 1) increasing oil or gas production, 2) avoiding excessive water production, 3) staying within the desired zone, or, 4) improving the performance of further stimulations. Several operators have utilized the gun numerous times, and although not all cases were successful, the total effect of all of the operations resulted in a substantial increase in production.

There have been failures. A review of the information provided by the operators, both from the PTTC Kansas survey and customer feedback to J Integral, indicates obvious reasons for the majority of the unsuccessful operations. Primary reasons for unsuccessful results are: 1) attempts to stimulate depleted reservoirs, 2) water present in formation adjacent to perforations, thus unavoidable, 3) well was adequately stimulated previously, 4) poor quality casing, resulting in casing splitting, and 5) poor cement job, resulting in collapsed casing.

To lessen the possibility of failures on GasGun™ jobs, the operator must carefully review the subject well and reservoir. An analysis of the productivity of the well, via production and/or pressure transient tests, should be conducted to determine if 1) the wellbore has a positive skin present and further stimulation should enhance productivity 2) adequate reserves are in place, and, 3) the zone to be treated does not contain a zone of high water saturation that could result in extremely high water production, if treated. In addition, the casing must be of good quality and a bond log has been run to determine the presence and bonding of the cement in the vicinity of the zone to be treated. It is extremely important to verify the competency of the cement behind the casing prior to using the GasGun™.