Completing oil and gas wells in unconsolidated (or poorly consolidated) sand may be a challenging task, but many effective solutions to control sand production are available, and range from Expandable Screens, Stand-Alone Screens to standard gravel packs, high rate water packs or frac packs, based on well and reservoir constraints.
In specific situations, such as dual selective completions in combination with multiple reservoirs or brown fields, conventional sand control methods may be too complex or not cost effective. As a result, some of the levels have to be completed without any sand control and therefore experience sand production during the life of the well, usually mitigated reducing the rate.
Sand production from conventional completions is a problem that eni E&P had to face in the past and many attempts had been made to find suitable chemical products for rigless remedial jobs.
This paper presents a new sand conglomeration treatment that creates an ionic attraction between the sand grains and fines using non damaging water base fluid. Besides the ability to mitigate sand production, it contributes in reducing/stopping fines migration and, therefore, minimizing near wellbore damage and allowing to increase the Maximum Sand Free Rate (MSFR).
After testing this new chemical product in clean sand environments, in Congo (oil producer) and Egypt (gas producer), eni E&P decided to try this technology in the multilayer gas-bearing Adriatic formation characterized by a sequence of sand strata interbedded with shale that provides an average gas permeability lower than 20 mD.
In the first part of the paper the chemical product will be shortly described, then four applications will be presented, with particular reference to field aspects, lessons learned and economic impact.
