Juru Bor (Driller) flashcards

35 cards. Read the term and the definition here. The deck at the top of this page is optional.

Hierarchy of control

Order of risk controls from most to least effective: elimination, substitution, engineering controls, administrative controls, then personal protective equipment. PPE is the last line of defence and never replaces an engineering control.

Permit to work

A formal written authorization for high-risk tasks such as hot work, confined space entry, or energy isolation. It defines the hazards, controls, and validity period, and becomes void when conditions change or the shift ends.

Confined space gas test order

Test oxygen first, then flammable gas, then toxic gases such as hydrogen sulphide and carbon monoxide. Entry normally requires oxygen between 19.5 and 23.5 percent and flammable gas below ten percent of the lower explosive limit.

Lockout tagout verification

Isolate all energy sources, apply a personal lock and tag, then prove zero energy by test or try-out. Only the person who applied a lock may remove it, and stored energy such as pressure must be released first.

Hydrogen sulphide properties

A colourless, heavier-than-air gas that is flammable and deadens the sense of smell at higher concentrations. Breathing apparatus is required at the immediately dangerous to life concentration of one hundred parts per million.

Hook load calculation

Hook load equals the buoyed weight of the drill string plus drag and any overpull. Buoyancy reduces string weight by the ratio of mud density to steel density, so the derrick rating must cover the maximum anticipated load.

Drill pipe steel grades

Common API grades are E-75, X-95, G-105 and S-135, where the number is the minimum yield strength in thousands of pounds per square inch. Higher grades carry more load but are more sensitive to hydrogen sulphide.

Crown-o-matic function

An anti-collision device that automatically stops the travelling block before it strikes the crown block. It must be tested regularly and is a critical safeguard during fast tripping operations.

Blowout preventer stack

The pressure control assembly at the wellhead, typically including an annular preventer and ram preventers for pipe, blind and shear service. Shear rams must be proven capable of cutting the specific pipe in the hole.

Rotary hose inspection

A high-pressure flexible line carrying mud from the standpipe to the swivel or top drive. Any damage exposing the reinforcement wire, or failure of the pressure test, requires removal from service.

Equivalent circulating density

The effective mud density in the annulus while circulating, equal to static mud weight plus the annular friction pressure expressed as density. It must remain below the fracture pressure at the casing shoe.

Kick detection while drilling

Indicators include a pit gain, flow from the well with pumps off, a change in pump pressure at constant stroke rate, and gas-cut mud. Any one indicator requires a flow check before continuing.

Yield point and gel strength

Rheological properties describing the mud's resistance to flow at low shear rates and its gelling when static. They govern cuttings transport and the pressure needed to break circulation after a trip.

Lost circulation remedies

Losses are treated in escalating steps: reduce equivalent circulating density, add lost circulation material, set a plug, then cement or run a liner. Total losses mean no returns and require immediate action.

Oil-based mud trade-offs

Oil-based mud gives better shale inhibition, lubricity and temperature stability than water-based mud, but needs cuttings treatment and stricter handling because of environmental and disposal requirements.

Stick-slip recognition

A torsional vibration where the bit stops and releases, seen as torque oscillation and erratic surface rotation. Remedies include changing rotary speed, reducing weight on bit, or improving mud lubricity.

Pump output formula

Pump output in gallons per minute equals pump displacement per stroke multiplied by strokes per minute and by volumetric efficiency. It is the basis for annular velocity and kill rate calculations.

Dogleg severity

The rate of change of wellbore angle, usually expressed in degrees per one hundred feet. Excessive severity increases pipe fatigue, torque and drag, and the risk of key seating.

Trip margin

Extra mud density added above pore pressure to compensate for the swab pressure created while pulling pipe out of the hole. It prevents an influx during trips.

Kill mud weight formula

Kill mud weight equals current mud weight plus shut-in drill pipe pressure divided by the product of 0.052 and true vertical depth. The result is the density that balances formation pressure.

Shut-in drill pipe pressure

The stabilized pressure on the drill pipe after a hard shut-in, representing the amount by which formation pressure exceeds the mud hydrostatic. It is the primary input to kill mud weight.

Driller's method

A well control procedure that first circulates the influx out at the slow circulating rate using the original mud weight, then circulates weighted kill mud. It is simpler but imposes higher shoe pressure than wait and weight.

Wait and weight method

A well control procedure where the mud is weighted up first, then kill mud is circulated in a single pass to remove the influx. It keeps casing shoe pressure lower than the driller's method.

Hard shut-in

Closing the blowout preventer with the choke closed, then opening the choke to read pressures. It minimises the volume of influx entering the well and is the preferred response to a kick.

Sling angle tension

The tension in each leg of a two-leg sling equals the load divided by twice the cosine of the angle from vertical. As the legs approach horizontal, leg tension rises sharply.

Wire rope rejection criteria

Reject a sling with ten or more broken wires in any lay, five in one strand, or with kinks, bird-caging, corrosion, or a missing identification tag. Safety factors are commonly five to one.

Critical lift plan

Required for lifts above roughly seventy-five percent of rated capacity, for tandem lifts, and for non-routine loads. It defines the rigging, the path, the exclusion zone, and the signaler.

Manual handling technique

Keep the load close to the body, bend the knees, keep the back straight, and avoid twisting while lifting. Use two people or mechanical aids for loads above about twenty-five kilograms per person.

Fire classes and agents

Class B fires involve flammable liquids and are fought with foam, dry chemical, or carbon dioxide. Class A involves solids, Class C electrical equipment, and Class D combustible metals.

Hydrogen sulphide rescue rule

Never attempt a rescue in a hydrogen sulphide atmosphere without breathing apparatus, because the gas rapidly causes loss of consciousness. Approach from upwind and uphill, and give oxygen to a conscious casualty.

First aid priorities

Follow danger, response, airway, breathing and circulation, then control severe bleeding with direct pressure. Cool burns with clean running water for at least twenty minutes and cover with a sterile dressing.

Muster and headcount

On the alarm, personnel proceed to the designated muster point and report in. The person in charge checks names against the rig list before any search and rescue is mounted.

Tour handover content

The outgoing crew briefs the incoming crew on well status, mud properties, downhole tools, open permits, and any abnormal pressure, pit or equipment behaviour. Both parties sign the record.

Stop-work authority

Every crew member has the right and duty to stop a job when an uncontrolled hazard is seen. The stop is logged, the hazard is controlled, and work resumes only with agreement.

Daily drilling report

The formal record of the operation, including depth, mud weight, bit hours, pump strokes, downtime codes and incidents. It is a legal document retained in the well file.