Page 197 - Handbook Of Multiphase Flow Assurance

194 6. Production chemistry and fluid quality

Test procedures for some of the scale tests are also available from NACE, but in many cases
are developed or updated by companies or laboratories individually.
Test procedures for the majority of other flow assurance issues are developed by compa-
nies or laboratories individually.
Some test standards as ASTM D97 for waxy oil pour point are adopted or modified.
Both laboratories and test equipment vendors may recommend the test procedures. Every
test procedure should be reviewed by operator company specialists to ensure that it ade-
quately reflects the operating conditions expected in the planned production system.

Chemical injection systems

Chemicals are usually deployed through chemical trunkline with branch lines equipped
with metering valve systems. Chemicals may also be deployed with point-to-point chemical
lines for systems which require high reliability of chemical delivery.
Chemicals may be delivered into the lower wellbore with downhole chemical injection,
into the upper wellbore with injection above SCSSV or from tree, into the tree, into the jumper
with injection from tree or a dedicated line, into the flowline or riser with a dedicated line,
and topsides.
Chemicals may also be deployed into the reservoir with injection water through a water
injection pipeline, into the reservoir with squeeze treatment through a service flowline.
Processing equipment may be located on surface (onshore or topsides offshore), subsea
(separation, boosting, pumping) or subsurface (downhole separation or homogenizing, or
subsea caisson separation). Chemicals may need to be injected into processing equipment by
the point-to-point method.

Comparative economics of production chemicals

Typical dosages of chemicals in the 50–500 ppm range were shown in Chapter 1. In most
cases the initial production starts at elevated chemical dosage to ensure the reliable startup
of production.
Subsequent periodic reviews of chemical effectiveness and economics may be done
to check whether the injected dosage for each chemical is sufficient, too high or too low.
This should be done in concert for all chemicals injected at a facility because many chem-
icals may affect each other's performance. So, an increase of corrosion inhibitor dos-
age may lead to reduced performance of demulsifier, low dosage hydrate inhibitor and
some other chemicals. This may lead to loss in separated water quality and incidents of
noncompliance.

Product fluid quality

The product of petroleum production includes hydrocarbon oil, hydrocarbon gas and pro-
duced water.