The correct selection, engineering and maintenance of drilling fluids is critical to the success of the drilling operations. Each member of the rig team must understand their responsibilities to ensure:

• the work required to mix and/or treat the drilling fluids is carried out safely and economically
• any discharges are handled in an environmentally responsible manner
• all health risks associated with chemical usage are controlled
• the drilling fluids meet the Company specifications and standards required
• there is no damage to the well bore which may effect production or logging.

General Responsibilities

The general responsibilities for planning, preparing and maintaining drilling fluids are outlined below:

Toolpusher Responsibilities

• ensure that all the equipment associated with the handling and treatment of mud is functioning correctly and that the Drill Crews check and maintain all such equipment daily or as required
• ensure that there is an adequate supply of consumables, such as different sizes of shaker screens, hydrocyclone filters, mud cleaner screens, degasser valves and spare parts to repair the equipment on site.

Drilling Supervisor Responsibilities

• ensure that the drilling fluid is handled, maintained and treated in a manner which fulfils the requirements and objectives of Company as outlined in the Drilling Programme or according to the drilling situation
• ensure that where necessary the environmental objectives of the drilling fluid programme are met at the well site
• ensure that the current policy on measurement and the reporting of Oil On Cuttings is adhered to at the well site
• ensure that the disposal of all fluid and wellbore materials conforms with all relevant regulations and the requirements outlined in the drilling fluid programme
• ensure that the Mud Engineer monitors and reports all drilling fluid losses/dumped using the approved report form on a daily basis
• liaise with the Mud Engineer in determining drilling fluid and associated material requirements and ensure timely requisitioning of same (minimum 3 days ahead)
• ensure that the quantities of barites at the well site are maintained above the minimum levels as determined by Company policy
• ensure that the routine testing and reporting on the drilling fluid is carried out as per Company requirements by the Mud Engineer with updated tools
• ensure that up to date copies of all material health and safety data sheets are kept at the rig location
• to prepare transfer sheet
• to review final mud report
• to advise senior operations engineer whenever problems arise

Driller/A. Driller Responsibilities

• ensure either through instruction, or by a pre-inspection tour prior to commencing his shift, that all solids removal equipment is functioning correctly and that the mud pits are lined-up correctly.

Derrickman Responsibilities

• assume responsibility for all activities that take place around the mud tanks
• liaise closely with the Mud Engineer to ensure that the mud is being treated or mixed properly
• ensure that the mud pits are lined up correctly to the mud pumps
• ensure that the solids removal equipment is functioning correctly under mud engineer’s supervision and keep the Driller and mud logger advised of any problems necessitating a shutdown of the drilling operation, so that this may be accomplished in a timely manner

Mud Engineer Responsibilities

• monitor and actively maintain the drilling fluid properties to the Company specifications as outlined in the drilling fluid programme
• advise the Drilling Supervisor of all drilling fluid related problems as and when they occur, recommend the appropriate treatment and chemicals required to return the drilling fluid to specification
• provide the Drilling Supervisor with an objective technical and commercial overview of the drilling fluid operation. Making recommendations for improving the programme or operation as and when necessary (in pre-spud meeting or during drilling )
• determine, manage and supervise all treatments to the drilling fluid. All treatments shall be based on sound technical evaluation and pilot testing
• issue written instructions to the rig crew personnel for all mixing requirements and copy these instructions to Drilling Supervisor and Tool Pusher.
• determine drilling fluid and associated material requirements (e.g. shale shaker screen size and type) and communicate to Drilling Supervisor to ensure timely requisitioning of same
• ensure correct operation and optimisation of the solids control equipment to:
• minimise fluid losses thereby reducing environmental pollution and drilling fluid costs
• control low gravity solids levels in the drilling fluid thus improving drilling fluid performance and reducing chemical maintenance costs
• ensure that all Company policies relating to the movement and containment of oil based drilling fluid and diesel at the rig site are strictly adhered to at all times
• compile all Company required reports relating to the transfer, storage, use and maintenance of all drilling fluids and related additives and equipment
• work with the Drilling Supervisor, Toolpusher and Safety Representatives to maintain safe working practices by:
• Actively participating in all pre-job safety meetings
• Ensuring all relevant personnel are aware of and adhere to the safe handling procedures of all drilling fluid chemicals and equipment
• perform quality control checks at the rig site to maintain strict quality control of all drilling fluid and bulk chemicals
• Report on a weekly basis to the Drilling Supervisor all drilling fluid losses/dumped using the approved report form
• Compile all drilling fluid recaps in a timely manner and ensure that they contain encountered problems, accurate information, objective conclusions and recommendations that will facilitate the effective planning of future wells
• provide the total weight of mud in sand traps, pits and reserve tanks to the barge engineer.