FS Training (general)3 Flashcards
You are mixing cement with a 38% water bwoc water/cement ratio which API class is this cement
D or H
API uses a unit called BLANE to qualify for the fineness of a cmt, a BLANE fineness of 1800
Class G is a fineness of 1800
API class G and Class H cmt are extensively used in the oil fields over a wide range of dept…
Class H is more retarded compared to class G because class H is coarser
From the following cmt hydration chart match the diff period
1 pre-induction period, 2 induction period, 3 acceleration period, 4 deceleration period, 5 diffusion period
Portland cement definition
Portland cement is made up of four main compounds: tricalcium silicate (3CaO · SiO2), dicalcium silicate (2CaO · SiO2), tricalcium aluminate (3CaO · Al2O3), and a tetra-calcium aluminoferrite (4CaO · Al2O3Fe2O3). In an abbreviated notation differing from the normal atomic symbols,…
What are the main salts used as accelerators
CaCl
What is the normal concentration range (%BWOC) of CaCl
1-4%
Select some extenders we use to lighten the cement slurry
(D20, D75 {A&B})
What is the range of concentration where NaCl work as an accelerator
3-5% (Up to 10% BWOW)
Concerning the utilization of bentonite choose the right statement for the list below that are c…
Bentonitic slurries present some part of fluid loss control when compared to neat slurries
1% BWOC Pre-hydrated bentonite is equal to 4% BWOC dry blended bentonite
Bentonitic slurries are a cheap alternative for light slurries
Why do we require 4 times less bentonite when it is pre-hydrated
Because the bentonite has more time to hydrate properly
Because the Ca ions of cement inhibits the hydration process of bentonite
Concerning D75 choose the correct statement
Reacts with cations in the cement to form silicate gel that is capable of binding extra water
Slurry presents usually better properties when compared to bentonitic slurries.
What are the reasons that make cement to lose fluid choose three
Differential pressure
Permeable medium (formation)
Water/cement ratio - Hydration needs
What are the types of fluid loss
Static
Dynamic
Choose the main mechanism of dispersion in a cement slurry
Turn most of the cement grains uniformly negatively charged
Which additive is used as a liquid dispersant
D80
How can strength retrogression be prevented in slurry design –
By adding 35% BWOC Silica
What is a secondary effect of most dispersant such as D21 D80
Retardation
Which additive do we use to increase the thickening time select the correct answer
Retarder
Which additive do we use to cover all temperature ranges to reduce fluid loss
Uniflac D168
