Day 2 Flashcards
(56 cards)
Where are you going to find methods to recertify chemicals that are past their shelf life?
On the QA/QC database
Name the differences between the old MSDS and the new SDS systems.
Proprietary chemicals are protected
The rating system is rolling from safest at 0 and most hazardous at 4 to safest at 5 and most hazardous at 1.
Or classifications flammability, aspiration, carcinogenicity, specific organ toxicity (repeated exposure and single exposure), skin irritation, and chronic aquatic toxicity
What is the difference between an XE code and a B code?
XE codes are for experimental chemicals.
B codes are for regional chemicals and may bleed over elsewhere.
List for types of damage.
Fines migration/swelling clays,
Scale deposits,
Organic deposits,
And water block
What treatments are there for fines migration/swelling clays?
Mud acid, clay acid, OMA, OCA, & gas well acid
What treatments are there for scale deposits?
ScaleSOLV, mineral acids, organic acids, & CAS
What treatments are there for organic deposits?
CleanSWEEP, solvents, mutual solvents
What treatments are there for water block?
Gas well acids & CleanSWEEP
Define skin
Dimensionless factor calculated to determine the production efficiency of a well by comparing actual conditions with ideal conditions.
Which reaction is faster, HCl on limestone or dolomite and why?
HCl on limestone. Because in the case of dolomite some or all of the calcium is substituted by magnesium in the reaction slowing it.
List of the sandstone acidizing stages.
Brine pre-flush HCl (or organic acid) pre-flush Main acid Over flush Diverter
Define brine preflush in sandstone acidizing
Displaces brines containing incompatible cations away from the wellbore.
Define HCl pre-flush in Sandstone acidizing.
Removes CaCO3 from the matrix to prevent the precipitation of CaF2.
Define main acid in Sandstone acidizing.
(mud acid) remove alumino – silicate formation damage.
Define over flush in sandstone acidizing.
Displaces spent acid away from critical matrix.
Define diverter in Sandstone acidizing
Stages before and after overflow stage as necessary and repeat stages
Why is diversion important in acidizing?
It prevents all of the acid from treating the most permeable zones without treating bless permeable areas of the formation which may not improve production in the list permeable areas.
List for different types of diversion techniques.
Mechanical,
Balls and Packers,
Bridging agents: salts and OSR
Chemical
Differentiate mud acid
Low temp, nonsensitive clays, low clay content
HCl preflush
Mud acid
Immediate flow back.
Differentiate clay acid
Low temp, non-sensitive clays, high clay content, HCl pre-flush, mud acid, clay acid, shut in.
Differentiate organic clay acid
Low temp, sensitive clays, any clay content
Organic acid pre-flush
Organic Clay acid
Immediate flow back
Differentiate organic Clay acid HT
Hi temp, sensitive clays, any clay content
Organic acid pre-flush
Organic clay acid
Immediate flow back
List the three methods of QA/QC for HCl
Specific gravity - can reveal percentage concentration,
titration – can detect acid strength,
HCl titration – can detect HCl versus another acid
Why use all three methods to QA/QC HCl?
To reduce the likelihood of another catastrophic event but using an acid other than HCl which is highly corrosive to the casing materials.
