In the Kenali Asam Field in Sumatra, Indonesia, most producing wells in the “b/400” horizon produced formation sand. Fracturing for sand control in this interval increased total field off-take from 900 bopd to 1900 bopd and controlled sand production.
Since 1990, over 200 hydraulic fracturing treatments have been performed in the Hassi Messaoud field in northeast central Algeria resulting in an average production increase of 5 m3/hr (750 bopd). The success of the stimulation program in this Cambrian age sandstone formation resulted from improved field practices of treating open-hole and slotted liner completions, and from the use of state-of-the-art fracturing equipment and engineering tools.
After several years of production, the production rates of some fractured wells have declined due to several reasons: reservoir depletion, salt precipitation from formation water breakthrough or injection water breakthrough, and fracture conductivity damage due to barium sulfate scale and asphaltene deposition. Since 1996, re-fracturing treatments have been conducted on nine wells in order to restore production by placing another propped hydraulic fracture in the same target drain.
The three case histories presented show exceptional, normal and marginal responses to the re-fracturing treatments. Explanations for the observed responses are presented and recommendations for the selection of new re-fracturing candidates in the Hassi Messaoud field are presented.
Author(s): Michael B. Marquardt, Diederik van Batenburg, Halliburton Energy Services; Rafik Belhaouas, Sonatrach
Paper Number: SPE 65186