first Flashcards
what is the equation for yield strength of pipe
describe the classification categories of cements (letter)
What is a pore pressure prediction method
what does a “Grade” of casing tell you
what is cement solid additives referenced to/by?
what is assumed for the external pressure when designing the surface and intermediate casing for burst pressure
what is the equation for plastic collapse pressure
letter constants given
Many abnormal pore pressure processes are simply the _______ of those which effect subnormal pressures
d-exponent relates the _______ with the drilling rate
pore pressure
what is the assumed pressure inside the casing when desinging production casing
describe design of christmas tree and wellhead
The d exponent ______ R and N, and changes in response to a change in the drilling rate.
R = rate of penetration
N = rotary speed
what are three results of exceeding burst pressure of casing
what are the equations for triaxial and biaxial collapse pressure
biaxial doesn’t conisder internal pressure
What is pore pressure prediction used for
what is yield strength Fy
The amount of strength before the pipe goes from elastic yield to plastic yield
what is compaction theory
what is the equation for elastic collapse pressure
describe how salt diapers can create an overpressured zone
Most pore pressure prediction techniques rely on _______ or ______ porosity
what are the properties of cement after setting
What two mud weight curves are used for casing design
What is the equation for fracture pressure
what is a drive pipe
what does a flex joint do
compensates for horizontal movement
What is W
weight on bit
what is the equation for dc exponent
how do you do liner interpolation for pipe grades
what is a tie back?
liner that is extended to the surface at a later date after installation
Describe downfaulting and overpressured zones
What is the horizontal method for undercompaction
cements are classified into categories by ____ grade
API
what are lightweight additives
what is mew
poisson ratio
Describe how abnormal pressure can be achieved by man-made methods
A decrease or flattening of the d exponent indicates a transition into an _____ pore pressure region (if all other parameters, including drilling fluid density do not change in the interval).
what is the base reference measurement for cement mixtures
matrix interval transit time is also a _______ of porosity
What is the equation with bulk density
what are the variables and exponents
R = rate of penetration
W = rate on bit
N = rotary speed
db = drill bit size
What is NCT
normal compaction trend (normally pressurized)
what is the equation for overburden stress
what is the relationship with porosity and depth
logarithmic
what is the casing design criteria for burt pressure
Give examples of pressure seals
what is the fineness of cement
What is a pore pressure prediction method (graphical)
Older formations normally present a degree of compaction _____ than new ones
what are the properties of cement in the fluid period
what are the types of cement
Bulk density depends on what
what is pipe (or casing) displacement
what is happenign here
transition zone into overpressured zone
what is meant by a state of stress in a formation
what are heavyweight additives
when adding additives to cement, extra _____ may need to be added to compensate for additives
water
what is the equation for pore pressure
how many ranges of casing joints are there
What are the two methods to determine matrix stress
what are low water additives
what is the middle curve
external pressure (right curve) minus internal pressure (left curve)
waht is the right curve
external pressure
what is the equation for horizontal matrix stress
What does an overpressured reservoir look like
what is the equation for the depth of the neutral point of casing
waht is the assumed internal pressure when designing production casing
What does normally pressured mean
What is the equation for posity versus depth
How can pore pressure be predicted durign drilling
These seismic data are, sometimes, the only _____ about the sedimentary rocks underground (in wildcats, for example).
what is the equation for transition collapse pressure
letter coefficients given
what are the advantages of using cement
Describe how a reverese fault can cause an overpressured zone
Describe the mud weight window
what are the types of loads on the casing
How does bulk density vary with depth
what does a slip joint do?
compensates for vertical movement
what is the equation for burst pressure
t = thickness
0.875 = safety factor
what is the christmas tree
When designing surface and conductor casing, assume that a fraction f (usually not less than 40%) of the length is evacuated by ____ and (1-f) fraction of the length remains filled with ____.
what is the equation for overburden stress
if axial stress isn’t being considered during the triaxial collapse pressure analysis, the analysis turns into what
biaxial, sigma a is removed -> ye goes to ye
Abnormal pressurized formations always require some means of _____ or _____ the pressure within the rock body
what are water to cement ratios
what is the equation to solve for the maximum length of casing as a function of max axial load
what is peq
the density of the mud and cuttings while it is being circulated by the mud pumps. almost always higher pressure
What is the equation for overburden stress
what is db
diameter of the bit
What is Eaton’s equation
what is R
rate of penetration
what does the curve to the farthest right show
internal pressure, transition matches up with figure to the left
what is the highlighted curve in red
collapse pressure
waht is the assumed external pressure when designing production casing
what is the middle curve
the external pressure (right curve) minus the internal pressure (left curve)
below applies to what
tension strength formula
what are cement retarders
what are the standard hole and string sizes
What is a normal compaction trend line
how do you predict and dedect abnormal pressure zones while drilling
What are the 12 indications of abnormal pressure
What is the dashed line on the pic below
safety margin
0.05 ppg - 0.1 ppg
A result from seismic survey is the ________ at several depths (time required by acoustic wave to traverse a length, normally 1 ft or 1 m, of formation).
What are the average transit times for matrix materials alone and matrix materials in water and oil
where are the two places tension failure can occur in the casing
_______ rocks should always be a warning to a driller that the pore pressure may be changing
what is the yield strength collapse pressure for non-thick wall pipe
what are the types of casing
What is N
rotary speed
why run casing
what is the left curve
internal pressure
for each sack of cement, a specific amount of ____ is added according to the API grade
water
What is a subnormally pressured reservoir
what is meant by the soundness of cement
what does a casing selection chart look like
what is the von misses failure criteria
How do the “horizontal methods for undercompaction” look like graphically
Describe types of casing threads and couplings
how is cement manufactured
what are the primary and secondary functions of casing
The collapse pressure resistance of a pipe depends on the _______
What is a spool
access to area between casings
what is the casing design criteria for tension
what is cement water referenced to/by?
what are liners and the three types
With normal compaction, R should _____ with depth which corresponds to an increase in d.
R = rate of penetration
d = d exponent
what is th bingham drilling model
There is a certain ______ to surge and swab to prevent fracture and kick
Speed
what is the least matrix stress
what are the setting properties of cement
what is this curve
collapse pressure
How do you determine porosity using the equivalent depth method
what is K and nw
constants
What is the equation for average transit time
Describe rounded thead, square thread, and integral thread
what is the wellhead
what does dc correct for
what is hole capacity
How are the D/t boundaries for collapse pressure determined
what is a conductor pipe
What are some causes for abnormal pore pressure
what is production casing
What are different regimes of collapse failure (depends on ratio D/t) for pipe
what is pipe (or casing) capacity
hwo do you predict and dedect abnormal pressured zones after drilling
what is the equation for transition collapse pressure
what is intermediate casing
where is the worst sinario for burst pressure for surface and intermediate casing
transition between gas and drilling fluid (blue/yellow meet)
what is the equation for yield collapse pressure for a thick wall cylinder
sigma r = radial stress
sigma t = tensile stress
describe how surface erosion can create over pressured zones
_____ problems and _______ are common problems in subnormal pressurized zones.
what is the equation fro formation fracture pressure
what is assumed for the internal pressure when designing the surface and intermediate casing for burst pressure
How do you predict abnormal pressure zones before drilling
what is the Basic composition of the clinker and Powder Portland cement
name some special cements
pipe is more likely to burst if it is under (tension/compression)
compression
what is meant by cement yield
Massive shales provide good ___________, but shales do have some permeability, so, given sufficient time, normal pressures will eventually be established.
what is the casing design criteria for collapse
what is cement liquid additives referenced to/by?
what are cement accelerators
What kind of pressure does this picture describe?
normally pressured or hydrostatic pressure
What is the equation for average porosity
What is a subnormal pressurized zone
Pore pressure varies with the ____ that causes the loss of hydration water in the matrix of some formations like shales.
what is surface casing
How do you history match using the Eaton equation
Adjust the Eaton equation coeffciient to match field data (3 in this case)
what are lost circulation additives
1 cement sack = ___ lbm
