Hollow glass beads on drilling fluid density
With the oilfield development, often faced with difficult exploration and development,
purpose layer buried depth, low formation pressure, then use under-balanced drilling
more. Therefore, more and more high to the requirement of drilling fluid.In order to
reduce the leakage and reservoir protection, as well as oil and gas layers in time, need
of drilling fluid density is lower than 1.0 g/cm3. With air drilling, foam drilling fluid,
and water-in-oil emulsion drilling fluid, the realization of the oil-base drilling fluid is
easy way, but there are many shortcomings, and drilling fluid performance itself
control difficult, rheology and hydraulics calculation complex practical problems such
as difficult to solve. Using high-performance glass beads in under-balanced drilling
has many advantages. Adding glass beads of the drilling fluid density decreased
significantly, and the added amount, the lower the density of drilling fluid.When the
content of T60 type glass beads was 40%, 0.870 g/cm3 density of drilling fluid.
Therefore, its biggest advantage is to adjust drilling fluid density within a certain
scope. Instant in high pressure high, the drilling fluid density is more stable, this is
because the hollow glass beads with low density high strength properties.
The influence of glass beads for drilling fluid lubricity
Glass beads spherical structure, which has high hardness, smooth surface, such as
features, rolling performance is good. Use it as drilling fluid additives, can play a role
similar to the bearing in the ball, greatly reduce the frictional resistance of drill pipe,
drilling fluid, fast bit drilling, improve the rate of penetration, and reduce the bit
wear.In the experiment, the Caspian sea region with diameter less than 0.9 mm of
glass beads, adding quantity is 5 ~ 20 kg/m3, the results make it required torque drill
pipe reduced 30% ~ 60%.
Now, in the exploration and development is difficult, purpose layer under the
condition of buried depth, low formation pressure with application of glass beads in
underbalance drilling has many advantages, one of the biggest advantages is the glass
beads can improve drilling speed; From the shaft to the differential fluid pressure of
formation fluid in the range of 0 ~ 6.9 Mpa, the common drilling method in
sandstone, limestone, shale drilling efficiency would lower 70 ~ 80%, and the glass
beads can reduce wellbore pressure significantly improve drilling efficiency.
Beads of recycling
Proportioning cost, because of the large dosage of hollow glass beads are relatively
high, can be recycled to become important factors restricting the popularization and
application of the glass beads drilling fluid can, and only when the beads for 50 ~
100%, the recovery of hollow glass microsphere, the cost of drilling fluid can with the
cost of conventional water-base drilling fluid.
Belonged to non-newtonian fluid, drilling fluid for non-newtonian fluid, the
sedimentation rate related to the rheology, has nothing to do with the density
difference between the medium. Based on this principle: recycling glass beads,
especially in the water-base fluid recycling glass beads, water damage fluid rheological
property can be used qualitative methods.In essence, is the drilling fluid from the
Newton fluid into the Newtonian fluid. A series of data show that recovery rate and
final reduced with increase with the increase of the amount of dilution. This method is
applicable at the scene, only will be separated from the solids control equipment of
the drilling fluid and completion fluid discharge to prepare a good pool, and then add
plenty of water, good beads will be floating on the surface of the water.
This article from the guest baba