Lightweighting Drilling Fluids made with 3M™ Glass Bubbles HGS Series
3M™ Glass Bubbles HGS Series are engineered hollow glass spheres used as density-reducing agents in oil and gas drilling fluids and cements. They are specially formulated for a high strength-to-weight ratio, allowing greater survivability under demanding downhole conditions.
Glass bubbles help reduce the density of water-based and oil-based drilling fluids. Densities as low as 5.5 lb/gal (0.66 kg/l) can be attained when the base fluid is a synthetic oil. Glass bubble-based fluids permit at balance, near balance and underbalanced drilling, and also allow measurement while drilling.
3M glass bubbles-based fluids control density efficiently, process easily at rig site and are compatible with surface cleaning and other downhole equipment. These fluids also are ideal for the range of temperatures, pressures and hostile environments found downhole.
3M™ Microsphers Application Guide (PDF, 767 Kb)
Drilling fluids or muds made with 3M glass bubbles HGS series can provide an economic alternative to aerated drilling fluids. For example, unlike aeration, glass bubbles don’t require expensive compressors – they can simply be mixed with a venturi hopper. And because air is never in contact with the drill string or steel casing, 3M glass bubbles can help reduce the likelihood of corrosion.
These reduced-density fluids are homogenous, incompressible and stable. They provide good borehole stability and excellent hole cleaning. And, they are so predictable that at-balance or near-balanced drilling can be used even in sensitive strata, without significant risk to the formation.
Low density drilling fluids made with 3M glass bubbles offer:
- Predictable density reduction
- Homogenous, incompressible, stable fluids that allow measurement while drilling (MWD)
- Excellent performance in many existing mud systems
- Added lubrication to the drillstring and reduced casing wear
Use of 3M™ Glass Bubbles in Drilling Fluids – General Guidelines (PDF, 1 Mb)
At the bottom of the borehole, there is a “tug of war” going on between two pressures. On one side is the formation pressure. If too great, the formation pressure may drive water, sand, oil or gas into the wellbore – possibly causing a blowout.
On the other side is the hydrostatic pressure from the weight of the drilling fluid column. If hydrostatic pressure exceeds formation pressure, it may drive drilling fluid into the formation, causing serious problems such as loss of circulation and formation damage.
In drilling fluids without glass bubbles, the drilling fluid column exerts greater hydrostatic pressure than the surrounding rock’s formation pressure, which can drive drilling fluid into the formation. The addition of 3M glass bubbles achieves a balance between hydrostatic pressure and formation pressure. The deeper the wellbore, the lighter the drilling fluid must be in order to maintain this balance.
Increasing Oil Well Production by Maximizing Under-balance during Perforation (PDF, 361 Kb) By Melvin Devadass, 3M Malaysia
3M glass bubbles are non-volatile, stable additives that provide drilling muds with durable low-density properties, both during and after a drilling job. They are compatible with oil, water and brine-based drilling fluids or emulsions. Additionally, muds formulated with 3M glass bubbles can potentially be re-used on multiple neighboring wells where low-density drilling is required, resulting in further cost savings.