Drilling fluids are fluids that are used during the drilling of subterranean wells. They provide primary well control of subsurface pressures by a combination of density and any additional pressure acting on the fluid column (annular or surface imposed). They are most often circulated down the drill string, out the bit, and back up the annulus to the surface so that drill cuttings are removed from the wellbore.

Functions of Fluids

• To remove the cuttings from the bottom of the hole and carry them to the surface.
• To transmit hydraulic horsepower to the drill bit.
• To cool and lubricate the drill string and bit.
• To exert sufficient hydrostatic pressure to control fluids encountered in formations penetrated.

*To minimize settling of cuttings and weight material in suspension when circulation is temporarily stopped. The mud, however, should have properties that allow the cuttings to settle in the surface system.

• To support and protect the walls of the hole.
• To reduce to a minimum any harm to the formations penetrated.
• To ensure maximum information about the formations penetrated.

Test and Mud Properties

Various properties of the mud are measured as an indication of the performance of the mud in the hole.

This stage comprises the following activities:

Density Or Mud Weight

Density Or Mud Weight affords a measure of the hydrostatic pressure of the mud column.

Viscosity

Viscosity is a measure of the internal resistance of a drilling fluid.

Plastic Viscosity

The Plastic Viscosity depends mainly on the friction between solids and the liquid.

Yield Point

Yield Point is a measure of the attractive forces between active clay particles in the mud under flowing conditions.

Gel Strength

Gel Strength is a measure of the attractive forces of suspended particles in a liquid when that liquid is in a static state.

Filtration

The filtration test is a relative measure of liquid filtered into a permeable formation and of the cake left on the formation.

Sand Content

Sand Content is measured because sand is abrasive to the equipment that comes in contact with the mud and sand may cause trouble by setting in the hole or by increasing the mud weight.

Solids, Oil, And Water Content

Solids, Oil, And Water Content are measured not only as a basis for the control of the oil content of emulsion muds but also as an aid in the control of the performance of the mud.

Chemical Tests

Chemical Tests are made on the mud and filtrate as an aid in the identification of contaminants and in control of mud properties.

Types of Drilling Fluids

Water-Based Drilling Fluids

Oil-Based Muds

a- Invert Oil Mud

b- Relaxed Invert Oil Mud

Additives For Drilling Fluids

• Fresh Water, Low pH
• Brackish Water, Low Ph
• Gyp Treated, Low Ph
• Lime Treated, High Ph
• Fresh Water High Ph
• Low Solids
• Emulsions
• Oil-In-Water.
• Water-In-Oil
• Oil Muds
• Air, Gas, Mist
• Foam

The term “personal protective equipment” (PPE) refers to a group of products (e.g. safety helmets, safety footwear and harnesses, eye protection, gloves, high-visibility clothing, etc.) designed with the aim to protect users against low-, medium- and high-level hazards.

There are eight types of personal protective equipment critical for the defense of users against hazards.

Head protection

It’s will help you avoid any harm that may come to you from falling materials or swinging objects. Moreover, the head protectors are designed to protect you from knocking against stationary objects.

Head Personal Protective Equipment e.g., Helmets; Hard hats; Bump Caps; Guards.

Activities related: Oil and gas works location, construction, work in tunnels, driving motorcycles.

Hand protection

Potential hazards to hands and arms include skin absorption of chemical or biological hazards, chemical or thermal burns, electric shock, bruises, abrasions, cuts, punctures, fractures, or amputations.  Protective equipment includes gloves, finger guards, and arm coverings.

Examples of hand personal protective equipment e.g., Helmets; Hard hats; Bump Caps; Guards.: different types of work gloves and gauntlets; and wrist cuff arm nets.

Activities requiring hand personal protection equipment: construction and outdoor work; oil and gas works, chemicals and hazardous elements; manual handling of abrasive or sharp objects.

Eye and face protection

Selecting the most suitable eye and face protection should take into consideration the following elements:

• Ability to protect against specific workplace hazards
• Should fit properly and be reasonably comfortable to wear
• Should provide unrestricted vision and movement
• Should be durable and cleanable
• Should allow unrestricted functioning of any other required PPE

Injuries can be avoided simply by wearing the proper eye and face personal protection equipment. As examples of such PPE can be mentioned the following ones: Safety glasses and goggles; Eye and face shields; Eyewear accessories; Over specs; Visors.

Respiratory protection

Respiratory Protective Equipment (RPE) is a particular type of Personal Protective Equipment (PPE), used to protect the individual wearer against the inhalation of hazardous substances in the workplace air.  Respiratory Protective Equipment like breathing apparatus, full face or half-mask respirators, powered respirators, protective hoods, disposal face masks, detectors, monitors, etc. Adequate training on how users should use the equipment is always required.

Hearing protection

People should wear a hearing protector if the noise or sound level they are exposed to is close to or greater than the occupational exposure limits (OEL) for noise. For most jurisdictions, this occupational exposure limit is 85 decibels (A-weighted) or dBA.

Examples of hearing protection equipment:

• Earplugs and defenders;
• Noise meters;
• Communications sets;
• Acoustic foam.

Foot protection

The foot protection equipment is designed to protect the feet and legs against various hazards, such as extreme temperatures, crushing, piercing, slipping, cutting, chemicals and electricity.

As examples of foot protection equipment can be pointed out following ones:

• Safety Boots and shoes;
• Anti-static and conductive footwear.

Body protection

Some jobs require full-body protection, while others require only special protective clothing for the parts of the body exposed to possible injury.

Examples of body protection equipment:

• Life jackets;
• Clothing for specific weather conditions;
• High-visibility clothing;
• Harnesses, and others.

Height and access protection

The height and access protection equipment must be inspected periodically by a competent person to ensure it is still fit for use and the health and safety of users is not threatened in any way.

As examples of height and access protection equipment can be mentioned in the following ones:

• Fall-arrest systems;
• Body harnesses;
• Lowering harnesses;
• Rescue lifting;
• Energy absorbers, and others.