Abstract
Cementing a liner string from the older Codell wellbores down to the J-Sand formation has been an important project in the DJ Basin for Kerr-McGee. The existing Codell wellbores have been deepened with a liner string because in 1998 the J-Sand well spacing was reduced from 160 acres down to 40 acres. The decrease in the spacing requirements created an infill drilling and deepening program in the DJ Basin. Typical cement volumes for J-Sand deepenings liner strings have been small, requiring 35 sacks of cement. The small cement volumes combined with the high bottom hole temperature (265°F) and narrow casing/hole clearances have made cementing practices difficult to implement for the service companies and operators in the DJ Basin. Traditional cementing practices have resulted in a +/- 10% failure rate in cementing the liner strings. The 10% failure rate and the "gray hair" factor that comes with cementing liners has been overcome with the use of overseas technology. Instead of dry powder cement, a Fluidized Cement Premix (FCP) has been utilized and pumped on more than 100 liner cement jobs with no problems for the service company or operator.
The objective of this paper is to identify and evaluate the benefits derived from switching from the conventional dry slurry to the FCP slurry. The benefits will be shown through the use of a statistical comparison of job success plus cost and a qualitative comparison of cement bond log signatures. The economic benefits will be explored for both the operators and the service company.
