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Drilling Process
NAME: Tahir Tahirzade

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Contents
Synopsis
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3
Drilling Bits
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5
Well Cementation
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7
Risk Analysis in Well Drilling
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9
Artificial Lift
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10
Well Repair
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11
Borehole Geophysical Logging
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13
Safety Factors
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15
Conclusion
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References
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Drills usually have high
length diameter ratio that is capable of producing deep hole
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During the drilling process, chips that are
produced during the workpiece must exit
through the flutes to the outside of the tool
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Friction
heat is also generated when the drill bit
touches the workpiece during the
holemaking process
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Drilling fluid is referred to as “mud”
because of its appearance
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During the drilling of the well, the progress of the operation
will be monitored constantly and a range of tests and analysis carried out
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If hydrocarbons are present then a flow test is usually performed to evaluate the
production potential of the well
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During this time, any produced is normally flared and liquid hydrocarbons are
stored onsite tanks and trucked to a local refinery
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The drill
bit located at the tip of the drillstring, below the drill collar and the drill pipe
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There are different types of drill bits
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Polycrystalline Diamond
Compact Bits use synthetic diamonds
attached to the carbide inserts
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Various drilling designs are employed
for different results
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Different configurations work better on different formations, so a number of
different drill bits may be used on the well
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Drilling engineers choose the drill bits according to the type of
formations encountered, whether or not directional drilling is required
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Once the drill bit has been changed,
the complete drill string is again lowered into the well
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Drilling Fluids
Drilling deeper, longer and more challenging wells has been made possible by
improvements in drilling technologies, including more efficient and effective drilling
fluids
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There are different types of drilling fluids
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The base fluid
may be fresh water, seawater
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The surface interval
typically is drilled with a low-density water or seawater based mud that contains
few commercial additives
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They also are known to inhibit the formation of ice-like hydrates that
can accumulate around subsea wellheads and well control equipment, blocking
lines and impeding critical operations
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Shale inhibition is one of the key benefits of using an oilbased fluid
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Synthetic based fluids were developed out of an increasing desire to reduce the
environmental impact of offshore drilling operations
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Well Cementation
Cementing is used for a number of different reasons, cementing protects and
seals the wellbore
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In preparing a well for cementing, it is important to
establish the amount of cement required for the job
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Additionally, the required physical
properties of the cement are essential before commencing cementing operations
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Cementing
operations can be
divided into two
broad categories:
primary cementing
and remedial
cementing
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Zonal isolation is not directly
related to production; however, this is necessary task must be performed
effectively to allow production operations to be conducted
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Remedial cementing is usually done to correct problems associated with the
primary job
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Remedial cementing operations consist of two broad
categories: Squeeze cementing and Plug cementing
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It normally involves initiating a hole from the wellbore through
the casing and any cement sheath into the producing zone
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In order to achieve
production, the casing and cement are perforated to allow the hydrocarbons to
enter the wellstream
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Once the reservoir level has been reached, the gun then shoots
holes in the sides of the well to allow the hydrocarbons to enter the wellstream
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While the perforation locations
have been previously defined by
drilling logs, those intervals
cannot be easily located through
the casing and cement
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The most important consideration in selecting a perforator is choosing a gun
system that matches the requirements dictated by the completion
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Risk Analysis in Well Drilling
Risk connotes the possibility of loss and the chance probability of that loss
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In oil exploration there are many aspects of risk
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Because of probabilistic nature associated with the time of drilling completion
operations, to estimate the necessary time to rent all the required rigs, is
considered a complex task
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Therefore, several of them are risky
decisions
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Considering the assumption that the analyst can associate a theoretical random
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Drilling machines are one of the most dangerous hand operated pieces of
equipment in the shop area
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Listed below are safety
procedures common to most types of drilling machines found in the machine shop:
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Never make any adjustment while the machine is operating
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Use a brush
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Keep all guards in place while operating
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Maintenance Process
Artificial Lift
Artificial lift is a process used on oil wells to increase pressure within the reservoir
and encourage oil to the surface
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Even those wells that initially posses natural flow to the surface
that pressure depletes over time, and artificial lift is then required
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Although there are several methods to achieve artificial lift, the two main
categories of artificial lift include pumping systems and gas lift
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An emerging method of artificial lift,
gas lift injects compressed gas into the well
to reestablish pressure, making it possible
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The injected gas reduces the pressure on the
bottom of the well by decreasing the viscosity
of the fluids in the well
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Typically, the gas that is injected
is recycled gas produced from the well
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Occurring downhole, the compressed gas is injected down casing tubing annulus,
entering the well at numerous entry points called gas lift valves
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Pump System
The most common type of artificial lift pump system applied is beam pumping,
which engages equipment on and below the surface to increase pressure and
push oil to the surface
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Above the surface, the beam pumping
system rocks back and forth
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The sucker rods are
connected to the sucker rod pump,
which is installed as a part of tubing
string near the bottom of the well
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The sucker rod pump lifts oil from the
reservoir through the well to the surface
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Here, the production is forced against the pistons, causing pressure and pistons to
lift the fluids to the surface
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Connected to a long electric motor, the pump is composed of
several impellers, or blades, that move the fluids within the well
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An electric cable runs the length of
the well, connecting the pump to surface source electricity
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Previously abandoned
wells have been re-evaluated and found to respond to fracture stimulation using
newer methods; however, to accomplish this, the casing string must have integrity
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Smaller diameter casing will result in
increased friction pressure and therefore treatment rate restrictions
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The increased cost of stimulation
must be balanced with the need to achieve cement isolation
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It
has very bad impacts in the well, so it can delay oil production for a very long time
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The
choices range from simple changes in operating practices to expensive
completions, such as sand consolidation
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Some of the sand control techniques are available:
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Maintenance and worker

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Rate exclusion

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

Selective completion practices

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Plastic consolidation

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High energy resin placement

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Resin coated gravel

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Stand-alone slotted liners or screens

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Gravel packing

Borehole Geophysical Logging
The Borehole Geophysical Logging is a method capable of generating vertical
profiles integrating several geophysical methods in the same point
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On the way up, the probe performs measurements on the walls of the
borehole, which can determine radioactivity, resistivity, magnetic, sonic and
others
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Natural Gamma- The Natural Gamma method is capable of measuring
quantitatively the natural radioactivity of the rocks connected to a sampling
borehole
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The gamma profile is frequently
used in the lithological characterization, clay fraction definition in the sedimentary
package and stratigraphic correlation
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The
technique is intensively applied to studies of groundwater, gradient, geotechnical
applications, evaluation of saline water intrusions
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The measurement system is based in four
electrodes, being two from the transmission circuit and the other two from the
electrical potential measurement
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The resistivity method is frequently used in borehole studies for petroleum and
groundwater, as well as contamination evaluations, helping to characterize the
environment porosity, quality of groundwater and the stratigraphic correlations
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Offshore drilling rigs
have drilling equipment to conduct all the functions similar to the land drilling rigs
and have facilities peculiar to offshore operations
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In addition, there are lots of
specific services on board such as divers, meteorological measurements,
helicopter, etc
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All these factors make offshore rig complex and
sophisticated, and therefore offshore drilling costs are higher than the land drilling
costs for similar depth wells
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The small platform has a space only to
accommodate derrick and drawworks, so a kind of assist the work
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Human factors have been identified as causing or contributing to major incidents
from the worst accident in U
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commercial nuclear power plant history at the
Three Mile Island power plant in 1979 through to recent events
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In order to reduce these risks, safety professionals need to
know the important contribution that cognitive issues make in process safety and
environmental incidents
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In addition to drilling and building permits,
permits may be required because of air emissions, discharges to surface waters or
sewer systems, injection activities, stormwater discharges, impacts to threatened
or endangered species or their critical habitat, impacts to wetlands and other
environmental impacts, or impacts to other cultural resources
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Operators should ensure that operations are conducted in accordance
with local, state or federal regulatory requirements
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scribd
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rigzone
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http://petrowiki
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CIVIL ENGINEERING – Offshore Drilling and Production Equipment- S
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Okada, Y

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