Mr. Erik Milito - The House Committee on Natural Resources ...

34 API STANDARD 65-2
Bulk plant scales should be accurate and in proper working order. <strong>The</strong>se scales should be part of a regularly
scheduled calibration program. Copies of the calibration certification should be retained at the bulk plant. A certified
calibration technician should perform all calibrations.
Bulk plants should be equipped with proper sampling devices to ensure that multiple representative samples are
taken throughout each blend. <strong>The</strong> sampling device should be located in an area on the discharge line that ensures
that excess moisture cannot enter the sample containers.
Certain cement blends require specific loading best practices. Service company-specific best practices should be
used as appropriate.
5.9.2 Cement and Additive Lot Numbers
<strong>The</strong> service company providing the cement and/or cement blend should follow all established, documented company
procedures to ensure that all received neat cement is within acceptable specifications upon arrival at the bulk plant. In
addition, the lot numbers of all additives used should be documented for each cement blend. This information should
be contained in the paperwork associated with the particular job for which the blend is loaded. A minimum of two
samples of at least one gallon each of neat cement or blend should be documented, labeled, and retained. One of
these samples should be retained at the bulk plant and the other sent to the lab for verification testing (if
recommended). If verification testing is recommended, testing should be conducted with representative samples of
location water.
5.9.3 Transportation and Storage of Cementing Materials
All cement blends should be stored and transported in properly maintained bulk storage tanks. This includes physical
inspection of the pads and interior surfaces of the tanks prior to loading/bulk transfer and tank clean-out if weather
conditions allow. Allowing moisture into tanks during inspection will lead to possible degradation of cement properties
and difficulty unloading the bulk storage tank. Inspection and cleaning will ensure that no contamination is present in
the storage tank(s). In addition, discharge, fill, inspection port, and vent valves should be checked to determine that
no valves are malfunctioning. Rock catchers should be installed at key points throughout the bulk transport and
storage process. Rock catchers should be inspected and cleaned as needed prior to transfer.
Cement volumes to be loaded should take into account any bulk transfer losses that may occur. This is particularly
important in an offshore environment where losses in the bulk tanks of a boat and in transfer to the rig may be
significant.
5.9.4 Mixing and Pumping
Slurry density fluctuations can have adverse effects on slurry properties including: reduced or extended thickening
times, free fluid, retarded compressive strength development, extended slurry transition time, and reduced fluid loss
control. Additionally, density fluctuations can result in increased ECD, fracturing of weak formations, and the potential
loss of well control.
<strong>The</strong> cement spacer(s) and slurries should be mixed as closely as possible to the planned densities. Some variance in
density will occur with field mixing equipment but acceptable performance properties of the fluids should not be
compromised. Computer-aided density control mixing systems normally improve density control. Batch mixing may
be necessary if mixing on-the-fly methods are not acceptable.
Low density slurries, such as those containing hollow spheres, have a dry blend density very close to the density of
the mix water. A very small change in slurry density with these systems could result in a large variation in the solids
content and possibly unacceptable slurry performance. A system that controls the solid/liquid ratio of the slurry (and
not the density) should be used when mixing low density systems that will not perform acceptably if density is not
controlled within an achievable tolerance.