A “solids-free” fluid without bridg

A “solids-free” fluid without bridging agent, such as F LO -P RO T SF, can keep pressures in a 2-in. diameter, 15,000-ft coil to less than 4,000 psi. The “solids-free” fluid relies on elevated LSRV to control the invasion of filtrate into the formation. As fluid leaks off radially to the formation, the shear rate decreases and viscosity prevents further penetration. Depth of penetration will vary from formation to formation and is controlled by, among other things, temperature, overbalance pressure, formation permeability and porosity, and formation fluid viscosity.Solids-free fluids do not form a filter cake on the face of the formation creating a high-differential-pressure gradient, but rather a gradual gradient over some distance. This reduces the potential for stuck pipe in the non-rotating annulus.