With sand control being an issue for many operators; there is a prevalence of Open Hole Gravel Pack (OHGP) completions used in offshore reservoirs. Gravel packing is an industry recognized method of stabilizing the well bore and controlling sand in gas and oil producing wells. But while ensuring the longevity of the well it also entraps the filter cake formed by the reservoir drilling and completion fluids. These factors result in a lower production rate well and the need for higher drawdown. Therefore it is essential that the filter cake be removed along the length of the wellbore to ensure no unnecessary restrictions to production.

This process requires an integrated approach to well start-up. It begins with the completion fluid used and ends with the start-up/bean-up procedure. The completion fluid type is essential in determining the lift-off pressure required by the filter cake. This pressure needs to be accounted for by the start-up rates used. Subsequently this start-up rate must be achieved in a safe and timely manner to ensure that the completion is not compromised, via the bean-up procedure. This necessitates the need for synergy between Subsurface, Well Engineering and Operations departments.

The North Coast Marine Area (NCMA) operated by BG Trinidad and Tobago consists of 17 horizontal OGHP gas production wells; hence it is imperative that a well thought out start-up philosophy to ensure well productivity. The sands, which these wells are completed in, are characterized by their thin laterally extensive nature. These sands show relatively homogenous reservoir quality profile with good lateral connectivity. Currently NCMA produces from the M2, M4 and M6 packages, each with a NTG over 95%. These wells have been drilled in three phases over the past decade, the last being October 2009 to March 2010.

This paper describes these improvements, challenges to the program and attempts to examine the results to determine any relative gains in productivity of the wells.

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