Lessons Learned During Sand Control Operations in the Gulf of Mexico where Bridging is a Strong Possibility
Authors: Cotrell D. L. , Wood R. , Stanley D. , Chaudhary S. , Chavez M. , Hill R. , Hollier R. , Alonso D. 
Published: February 2024

Sand, or fines as some may call it, entering currently producing wells is one of the earliest problems faced by the Oil and Gas Industry in hydrocarbon recovery [Rogers, 1954; Carlson et al. 1992; McLeod 1994; JPT Staff 1995; Barrilleaux et al. 1996], and one of the toughest to solve in general [McLeod 1997]. Every year the petroleum industry spends significant capitol in cleaning and disposal costs, repair problems related to sand production, and lost revenues due to lower production rates due to mitigation efforts [Mathis 2003; Palmer et al. 2003]. Thus, sand control is, and should be, an integral part of well planning [Guerrero 2014] in unconsolidated reservoirs [Willson et al 2002; Chang 2006; Jaimes 2012], i.e., reservoirs where the rock has little or no natural inter-grain cementation. Sand production [Veeken et al. 1991; Subbiah et al. 2021] is caused by structural failure of the borehole wall rock due to drilling, degree of consolidation (very low compressive strength), the interaction between the rock and flowing fluids (production creates pressure differential and frictional drag forces that can combine to exceed the formation compressive strength), excessive drawdown causing fines and sand grain movement to the wellbore, or reduction of reservoir pressure. Sand production leads to adverse effects on various components in the wellbore and near wellbore area [Zamberi et al. 2014], such as tubing, casing, flowlines, and pumps, as well as surface equipment [Peden et al. 1984; Lidwin et al. 2013]. In addition, sand production may allow for the creation of downhole cavities [Peden et al. 1985] resulting in loss of structural integrity of the reservoir around the wellbore and ultimately possible collapse of the wellbore. Along with these possible issues, there is an additional economic impact in that sand must be separated out and disposed of at the surface and can be a few liters to several hundred cubic meters [Lidwin et al. 2013]. Decisions around sand production are not purely economic these days because regulatory and environmental restrictions have come to play a significant role in the decisions of how sand production will be handled. In general, what constitutes an acceptable level of sand production depends on operational constraints such as the ability to use erosion resistant materials, fluid separator capacity, sand disposal capability, and artificial lift equipment's capability to remove slurry from the well, but with that said, sand control methods that allow unconsolidated reservoirs to be exploited often reduce production efficiency. Thus, an effective design is always a balance between keeping formation sand in place without unduly restricting current and future productivity [Saucier 1974; Mathis 2003; Palmer et al. 2003; Lastre et al. 2013].

There are two primary methods of sand control these days, namely passive and active, where passive sand control uses perforation orientation and placement to try and mitigate sand production, while active sand control uses a more intrusive approach utilizing downhole filters [Tibbles et al. 2020]. Currently, the most popular and successful method of negating sand production is gravel packing around a downhole filter. In this method, gravel is deposited downhole by pure beta wave deposition in slightly deviated wellbores, i.e., wellbores having a deviation angle in the screen section less than about 50 degrees, or by what is normally referred to as alpha/beta wave deposition in highly deviated wellbores, i.e., wellbores where the screen section maximum deviation is greater than 50 degrees.