Abstract:
The major perforating challenge faced, is to clean the perforation tunnels and perforate as deep into the reservoir as possible, for optimum production performance. Operational challenges are faced in high temperature, side-tracked, gas wells. OMV Pakistan`s, Miano-7 (Side-Track), presented one such challenge. This paper presents how these challenges were faced and overcome, resulting in optimal perforating strategy for achieving superior production performance. Deepest* penetration charges available, with dynamic underbalance, were used to ensure low post-perforation skin. Perforation charges and gun conveyance technique used were compatible to the high temperature of the field. Underbalance conditions were required by the operator to avoid time consuming lifting operations and flowback of brine to the formation. Proper cleaning of perforation tunnels was also of importance for future production performance, which was achieved with dynamic underbalance. Operationally, wireline runs were minimized to avoid any risks of getting stuck or kinks in the wireline. This kink is often seen when perforating gas wells and occurs at the liquid-gas contact in the wellbore, when a high static underbalance is used. For Miano-7 ST, thiskink was successfully avoided by using a low static underbalance of 100 psi, supplemented by dynamic underbalance. The large dynamic underbalance created at the instance of perforating ensured that the crushed zone and debris was cleaned out of the tunnels. High shot density is very important in gas wells to keep turbulent skin effects low. This perforating strategy resulted in lowest postperforation skin, and negligible non-Darcy skin, for Miano-7 ST in the entire Miano field.
Page(s):
233-242
DOI:
DOI not available
Published:
Journal: Proceedings SPE-PAPG Annual Technical Conference, Volume: 0, Issue: , Year: 2008