Oilfield Well Blowouts and Coil Tubing Injuries

Working on an oil well is a hazardous job. Whether it’s the result of exposure to hazardous chemicals, falls, wellsite fires, explosions or contact with equipment, oil well injuries and fatalities continue to occur. Workers caught in the midst of a well blowout may sustain catastrophic injuries or even be killed.

A blowout occurs when a sudden spike in well pressure shoots the well’s contents from ground-level. Drilling wells sustain pressure from the earth’s crust and also use internal pressure to keep fluids circulating. However, disruptions can reverse the flow of well contents and drive them back to the earth’s surface with extreme force.

The sudden release of pressure at the surface can shoot equipment parts, snap heavy cables, and destabilize the derrick. Bystanders can sustain blunt force trauma, lacerations, amputation, and other concussive injuries. Blowouts also release flammable hydrocarbons that can ignite from sparks or friction, fueling explosions and rig fires that cause burn injuries. They can even tap toxic gases such as methane, carbon monoxide, carbon dioxide, and hydrogen sulfide.

Many oil and gas companies continue to put profit over safety, often resulting in poor supervision, faulty equipment, a lack of safety training and worker fatigue. When accidents occur, they are almost always the result of negligence or intentional short cuts taken by oil and gas companies.

Oil field accidents can lead to any number of debilitating injuries, including amputations, bone fractures, severe burns, blindness, neck and spine injuries, hearing loss, post-traumatic stress disorder (PTSD), permanent disfigurement and traumatic brain injury (TBI).

To prevent a well blowout in drilling, workers should be trained properly and know how to act in the event of an emergency. Those on duty should be aware of how their blowout prevention equipment behaves in extreme conditions and BOPs should be kept in good condition to continue functioning accurately.

Catastrophic Well Blowouts

What is a Blowout?
Blowouts are a release of built-up pressure from oil drilling efforts. When oil collects underground, it forms an oil field. When people drilling for oil attempt to tap into this concentration of oil, the pressure can build up and cause a blowout. Oil well blowouts cause death and catastrophic injuries to workers near the scene of a blowout.

Why do oil wells explode?
Oil well blowouts can occur when the rig applies too much pressure during the drilling, causing the pool of underground oil to erupt. When the drill encounters a pressurized zone underground and the gravity of the drilling mud fails to counteract the pressure, it causes a sudden rush of pressure up the system.

What causes a blowout during drilling?
An uncontrolled flow of formation fluids from the wellbore or into lower pressured subsurface zones (underground blowout). Uncontrolled flows cannot be contained using previously installed barriers and require specialized services intervention.

Types of Blowouts
"Well blowouts" at the surface can cause the oil or gas to be ejected. It could also bring up mud, stones, and sand. These could be caused by sparks from rocks rubbing together or from another type of heat source.

Preventing Blowouts
A Blowout Prevention System (BOP) is used as an extra layer of protection when drilling in high-pressure areas. The BOP consists of several valves installed at the top of the well that allows workers to control pressure or close a well off completely. BOPs are critical to the safety of drilling operations, and they are required to be inspected and maintained frequently.

A blowout preventer (BOP) is a specialized valve or similar mechanical device, used to seal, control and monitor oil and gas wells to prevent blowouts, the uncontrolled release of crude oil or natural gas from a well. They are usually installed in stacks of other valves.

The first sign that a blowout may be eminent is an event known as a “kick”. The kick occurs when the pressure balance is off. If this kick is not controlled, the result could be a blowout. There are certain signs that workers can lookout for when it comes to kicks. The rate at which drilling takes place may suddenly change or the rate of surface fluid may change. Workers also need to be on the lookout for change in the pressure of the pump or a reduced weight in the drill pipe.

What is the difference between a blowout and a kick?
A kick is defined as flow of formation fluids or gas into the wellbore.
A blowout is the uncontrolled release of the fluid or gas, gained through the kick. A blowout can take place at the surface or into another formation (underground blowout).

Blowout preventers were developed to cope with extreme erratic pressures and uncontrolled flow (formation kick) emanating from a well reservoir during drilling. Kicks can lead to a potentially catastrophic event known as a blowout. In addition to controlling the downhole (occurring in the drilled hole) pressure and the flow of oil and gas, blowout preventers are intended to prevent tubing (e.g. drill pipe and well casing), tools and drilling fluid from being blown out of the wellbore (also known as bore hole, the hole leading to the reservoir) when a blowout threatens.

Blowout preventers are critical to the safety of crew, rig (the equipment system used to drill a wellbore) and environment, and to the monitoring and maintenance of well integrity; thus blowout preventers are intended to provide fail-safety to the systems that include them.

Oilfield Coil Tubing

Drilling sites feature incredibly large and dangerous pieces of equipment. They’re required for pulling pipe, drilling, mixing mud, and many other jobs that occur on the worksite. These types of equipment are large and heavy. When they’re faulty, the results can be fatal. Heavy machinery on work sites is required to be safe for workers to use, meaning that it must be well maintained. These workers are also required to be provided with adequate training for operations and safety. When an employee isn’t trained correctly, or when the equipment isn’t up-to-code, that’s when accidents happen.

What does coil tubing do in the oilfield?
Coiled tubing is a cost, and time-effective solution for well intervention operations. Instead of removing the tubing from the well, coiled tubing is inserted into the tubing against the pressure of the well and during production. The coiled tubing is a continuous length of steel or composite tubing that is flexible enough to be wound on a large reel for transportation. The coiled tubing unit is composed of a reel with the coiled tubing, an injector, control console, power supply and well-control stack. The coiled tubing is injected into the existing production string, unwound from the reel and inserted into the well.

Coiled tubing is chosen over conventional straight tubing because conventional tubing has to be screwed together. Coiled Tubing fulfills three key requirements for downhole operations on live wells by providing a dynamic seal between the formation pressure and the surface, a continuous conduit for fluid conveyance and a method for running this conduit in and out of a pressurized well.

The most common applications for coiled tubing are cleanout and perforating the wellbore, as well as retrieving and replacing damaged equipment. A jetting tool can be used to remove scale from a producing well. The tool consists of a rotating head with opposing tangentially offset nozzles and a drift ring.

Jetting action from the nozzles removes scale from tubular walls while the drift ring allows the tool to advance only after the internal tubular diameter is clean. Nonabrasive fluids are pumped through the nozzle for removal; abrasive beads are used to remove hard scales. When tubulars are completely plugged, abrasive jetting is used in conjunction with a powered milling head.

Additionally, some advances in coiled tubing allow for real-time downhole measurements that can be used in logging operations and wellbore treatments. Enhanced Oil Recovery (EOR) processes, such as hydraulic and acid fracturing, can also be performed using coiled tubing. Furthermore, sand control and cementing operations can be performed via coiled tubing.

Oilfield Coil Tubing Blowout

OSHA Case Study:

Cudd Pressure Control, Inc.
August 3, 2001: An employee was preparing a spool on a coil tubing unit for change out and replacement with another spool containing different diameter pipe or tubing. A coil tubing unit is a mobile unit that carries 15,000 to 20,000 feet of pipe coiled around a spool for deployment into existing oil or gas wells. The employee was standing on top of the spool, about 12 feet above ground level.

As he cut the tubing to free it from the injector, the approximately 10-foot in diameter spool he was standing on began to turn slowly. The spool's hydraulic system was engaged, the brake was not set, and the spool was not secured or chained. In addition, the employee had tied his safety lanyard off to the rim of the spool. Tied at the waist and unable to unhook his lanyard, he was subsequently pulled through a 10-inch gap between the spool and its frame.

The lanyard broke away and the spool then made several revolutions before another operator could climb up into the control room to stop the spool. The incident resulted in a fatal injury to the employee, who was asphyxiated.

Contact Miller Weisbrod

We understand that many oilfield injuries involve permanent damage that may impair your ability to ever work the same way again. We will make sure to include lost wages, future lost earnings, pain and suffering and all medical claims in our settlement demands. Miller Weisbrod's experienced Oilfield Injury Attorneys are prepared to take your case to court as well.

If you have suffered an oilfield injury or a loved one died in an oilfield accident, please contact our offices today at 214.987.0005 or toll free at 888.987.0005 for a free consultation. You may also contact us through the form on this page for answers to your important questions or to schedule an appointment.