GRAVEL PACK COMPLETIONS SUCCESSFUL HISTORY IN MEDITERRANEAN SEA GAS FIELDS, EGYPT By
W.Gabr, S. Zayed, Belayim Petroleum Co. (PETROBEL)
A
bstract
Mediterranean Sea offshore concessions are located about 30 – 60 km off the Northern Egyptian coast. More than 25 gas prospects have been identified. These accumulations are often characterized by several hydraulically independent reservoirs. Three gas-condensate fields were discovered by three exploratory wells in 1982, 1983 & 1995, finding several gas bearing intervals inside Wakar and Abu Madi Formations (Miocene age). Following, further 9 gas fields have been discovered identifying several lean gas bearing intervals inside Kafr El Sheikh Formation (Plioceneage). In 2002, a lot of wells started to produce sand causing severe problems to the surface facilities and reducing the concessions production potential. In 2003, a sand control campaign was undertaken in Mediterranean Gas fields to recover the full fields’ capacity using both Gravel Pack Completions (first time in Egypt in well PFM–7) and Expandable Sand Screen Completions (first time in Egypt in well PFM–8). By time, Expandable Sand Screen Completions proved its failure in many cases and are minimized to very limited cases. The aim of this poster is to highlight the advantage of Gravel Pack Completion technique used in North Port Said, Temsah & Baltim concessions over Expandable Sand Screen Completion technique focusing on successful case histories and its positive impact on production and reservoir potential.
INTRODUCTION
Most of the gas wells are producing from sandstone formations deposited in marine or delta environments. In the case of older and deep formations, sand grains are cemented by limestone or silica minerals, and in general the consolidation process is at a mature stage.
50 Petroleum Today
- February 2018
More recent deposits, (starting approximately from the Miocene) are partially consolidated and their degree of cementation is non-existent or extremely low. In such reservoir, the sand production risk is extremely high. In most cases, sand production leads to serious operative problems affecting production and safety. This factor is one of the most important constraints in developing reservoirs in weak sandstone formations and, consequently, one of the main factors that determine the profitability of the investments. Before 2003, Petrobel suffered from sand production resulting in severe damage to the surface and topside facilities with very dangerous gas leakage (risk of fire occurrence) and reduction of the production potential below the contractual DCQ. To overcome the sand production problem, an action plan was defined as follows: Ó Perform production test using wellhead desander unit (WDU) for the existing flowing wells to define the optimum sand free rate. Ó Completion of the new wells and workover of the existing wells with sand control technique. This paper is presented to highlight Petrobel sand control experience using both Gravel Pack and Expandable Sand Screen Completions in the operated Mediterranean Sea gas fields and their impact on the production potential in addition to the advantage of Gravel Pack Completion techniques over Expandable Sand Screen Completions.
SAND PRODUCTION DEFINITION
Sand production can be defined as follows: The failure of weak sandstone causes the detach of the grains which are transported inside the well by the produced fluids. The physical process can be described by a two stages
