Drilling Practices (Oil & Gas) Dr. H. Kwame Afaglo (PhD, BSc) 2009 : Drilling Practices (Oil & Gas) Dr. H. Kwame Afaglo (PhD, BSc) 2009
Drilling Practices (Oil & Gas) : Drilling Practices (Oil & Gas) Brief History of Nigeria Oil & Gas exploration
Confirmed results of oil in Nigeria was recorded as far back as 1908 by a German company – the Nigerian Bitumen Corporation and it explored for oil in the Araromi area between Ijebu Ode in the present Ogun State and Okitipupa in the present Ondo State.
After the World War 1, Nigeria minerals fell under the authority of the British. Consequently, the British usurping administration enacted the Mineral Oil Ordinance in 1914 to regulate the exploration of crude oil. The law empowered only British firms to discover Nigerian crude oil.
Drilling Practices (Oil & Gas) : Drilling Practices (Oil & Gas) “No lease or license shall be granted except to a British subject or to a British company
registered in Great Britain or in a British colony having its principal place of business”
Drilling Practices (Oil & Gas) : Drilling Practices (Oil & Gas) In 1973 Shell D’Arcy, an Anglo-Dutch consortium and subsidiary of the Royal Dutch Shell group, were licensed to explore oil over the entire geographical demarcation of Nigeria.
Since the exploration authority was given to Shell D’ Arcy (the forerunner of Shell Petroleum Development Company of Nigeria [SPDD]) they have had this edge over all other firms in the oil and gas industry of Nigeria.
Drilling Practices (Oil & Gas) : Drilling Practices (Oil & Gas) Coiled-Tubing Drilling
The process of driving a metal pipe down into a mineral reservoir at an angular position (between 300 to 900) aided by chemicals and pressure to extract oil and gas either from a new or depleted well.
Because this drilling technique is technologically advanced and the most used since the 1970’s, it is complemented with Basic Procedure, Health and Safety practices, as follows.
Drilling Practices (Oil & Gas) : Drilling Practices (Oil & Gas) http://www.youtube.com/watch?v=nCnzx_xNlDE
Please watch this six (6) minutes video.
Drilling Practices (Oil & Gas) : Drilling Practices (Oil & Gas) Basic Drilling Procedure
Clearly define the objectives of the well.
Question: Why use CT for this well?
Response: Is it Re-entry or new? Underbalanced, balanced, or over-balanced fluid? Hole size? Cuttings or transport?
Drilling Practices (Oil & Gas) : Drilling Practices (Oil & Gas) ii. Review the well history and mechanical condition of an existing well. If a new
well, review offset well data. Well should be screened in the three main areas of
mechanical condition, reservoir quality and issues, and directional considerations
for reaching the target.
Drilling Practices (Oil & Gas) : Drilling Practices (Oil & Gas) iii. Perform feasibility study and identify drilling hazards, risks and controls.
Drilling Practices (Oil & Gas) : Drilling Practices (Oil & Gas) iv. Obtain regulatory approval for pre-rig work and CTD operation. Perform pre-
CTD rig work.
Drilling Practices (Oil & Gas) : Drilling Practices (Oil & Gas) v. Begin site preparation review with the CT contractor.
Review CT equipment needed for the project and determine what equipment meets the requirements of this particular project.
Determine auxiliary equipment required and its position in relation to the CTD rig.
Determine required well-control equipment and determine proper configuration for the proposed well and anticipated conditions.
Drilling Practices (Oil & Gas) : Drilling Practices (Oil & Gas) vi. Choose a drilling fluid based on formation information provided and run wellbore
hydraulics calculations to determine if fluid and system are appropriate for the
well conditions.
Drilling Practices (Oil & Gas) : Drilling Practices (Oil & Gas) vii. Determine type of window-milling operation required for the well.
Decide if any open-hole logging is required and if the well will be perforated.
Drilling Practices (Oil & Gas) : Drilling Practices (Oil & Gas) viii. Write final drilling procedure. Set up and conduct a pre-spud meeting.
Make changes/additions to the procedure. Write any contingency procedures.
Prepare site for the rig and move in rig.
Drilling Practices (Oil & Gas) : Drilling Practices (Oil & Gas) ix. Ensure all equipments are inspected and maintenance records are available.
Confirm that all procedures are written and in place.
Call regulatory agency, directional tool personnel, directional driller and BHA supplier as well as any specialty tools, liner and liner equipment.
Drilling Practices (Oil & Gas) : Drilling Practices (Oil & Gas) x. Swap out milling fluid for drilling fluid and drill well according to directional plan.
Drilling Practices (Oil & Gas) : Drilling Practices (Oil & Gas) Record and report all required data during the drilling operation.
Run open-hole logs as required.
xiii. Run liner in open hole, if required. If cementing is necessary, cement liner
according to procedure.
Drilling Practices (Oil & Gas) : Drilling Practices (Oil & Gas) Log and perforate as necessary.
xv. Rig down CT unit and move off of well.
Drilling Practices (Oil & Gas) : Drilling Practices (Oil & Gas) xvi. Accumulate and assimilate all data from the CTD project.
Review with the CTD team the results from the project. Perform vendor review with each vendor.
Enter all data into the database. Make changes and document for future wells.
Drilling Practices (Oil & Gas) : Drilling Practices (Oil & Gas) Storage of oil and gas in appropriate tanks.
Transporting oil and gas.
Both storage and transporting of oil and gas are delicate processes, hence buttress the importance of Health and Safety Reulations.
Drilling Practices (Oil & Gas) : Drilling Practices (Oil & Gas) Safety and Emergency Equipments
As a pre-requisite one must be Health and Safety trained before getting onto a platform.
Health and Safety regulations must not just be established by the regulating body (preferably a government institution) but also inspected and monitored continuously and reports logged.
Drilling Practices (Oil & Gas) : Drilling Practices (Oil & Gas) Good knowledge of safety equipments store and positioning on board platform is another requirement.
Emergency engine kill systems – often required on engines and pump
engines to stop operations in time of emergence.
Drilling Practices (Oil & Gas) : Drilling Practices (Oil & Gas) Fire-fighting equipment – extinguishers (mostly CO2 and foam) should be provided at various vantage points as near port-a-cabins or offices and in the vicinity of fuel tanks.
H2S protective equipment and gas detection equipment – type, quantity and placement of H2S protective equipment maybe subject to legislation or corporate policy. Nasal mask, goggles.
Drilling Practices (Oil & Gas) : Drilling Practices (Oil & Gas) Eye wash station – typically located adjacent to the drilling fluid mixing facility
Personal protective equipment – often required for safe preparation of drilling fluids, e.g., apron, goggles and long-sleeved gloves for chemical handling. A chemical shower may also be required if corrosive chemicals are to be prepared.
Drilling Practices (Oil & Gas) : Drilling Practices (Oil & Gas) Alarms must be installed at vantage points to detect signals earlier to prevent accidents.
Functional communication equipments must be installed in every enclosed area and open spaces on the platform. E.g. radio, PA systems etc.
There must be standard safety procedures of which must be known by all and sundry on the rig.
Drilling Practices (Oil & Gas) : Drilling Practices (Oil & Gas) Safety drills must be carried out periodically. This would etch the safety regulations in everyone on site’s mind.
Safety and evacuation signs must be well and visibly posted at vantage points.
Departmental Emergency and First aid representatives must hold regular meetings and ensure company safety regulations are adhered to and in line with regulators policies.
Drilling Practices (Oil & Gas) : Drilling Practices (Oil & Gas) CONTINGENCIES
With oil and gas drilling being a complexity process, it is imperative that its management must have a contingence plan in other to cater for unplanned events. All operatives must be familiar with the contingence procedure. Some of the primary plans are:
Drilling Practices (Oil & Gas) : Drilling Practices (Oil & Gas) Stuck or damaged drillstring (due to hole conditions) - With proper monitoring of torque measure it would indicate constrictions of the drillstring of which the withdrawal of the drillstring does prevent a snap or damage to drillstring or head.
Open-hole sidetrack – May occur when the drill head goes off-direction. It can be monitored and signals plotted and interpreted to indicate head course for corrective measure.
Drilling Practices (Oil & Gas) : Drilling Practices (Oil & Gas) Lost circulation – Drilling fluid from wellbore could be caused by thief zones, faulty fractures etc. This could be resolved depending on volume and type of lost as ranging from ‘do nothing’ to ‘cement plugback and sidetrack’. Care must be taken in resolving this problem since heavy losses would compromise profitability.
Drilling Practices (Oil & Gas) : Drilling Practices (Oil & Gas) Liner running and cementing – technical processes must be adhered to based on planning else such glitches could be expensive to correct.
Drilling Practices (Oil & Gas) : Drilling Practices (Oil & Gas) Oil spillage clean-up
Oil spillage is known to destroy the eco system and environmentally hazardous yet it is a commonplace event. Oil spillage puts the lives of humans, flora and fauna at risk.
It is primarily the responsibility of the institutions that cause the spillage to clean it up. Also the governing bodies of the geographical location where the spillage occurred, NGOs and individuals.
Drilling Practices (Oil & Gas) : Drilling Practices (Oil & Gas) Some notable cleaning up approaches are listed below.
Oil spillage on land –
A trench is dag and Plastic bags are then inserted for onward collection of the polluted soil.
The spillage could be scraped and shovelled off for proper disposal.
A hydro gel could be applied to wash the oil off.
Drilling Practices (Oil & Gas) : Drilling Practices (Oil & Gas) Oil spillage in water bodies
Booms are laid within the spillage region so as to contain it and prevent it from floating further.
b. Scraping follows the boom spreading.
c. Then vacuum pumps are employed to suck the floating oil.
d. Spillage bagged and properly disposed off.
Drilling Practices (Oil & Gas) : Drilling Practices (Oil & Gas) Thought provoking
Are the Nigerian laws adequately enacted to protect the environment against oil and gas spillage?
Are the laws protecting the water bodies within the rig site?
Are there environmental contemplations towards the forth coming ‘Nigeria oil and Gas 2010’ at Abuja?
Drilling Practices (Oil & Gas) : Drilling Practices (Oil & Gas) References
Ayodele-aakar, F. (2000) Appraising The Oil & Gas Laws: A Search For Enduring Legislation www.jsd-africa.com/Jsda/Fallwinter2001/articlespdf/ARC%20-%20APPRAISING%20THE%20OIL%20and%20Gas.pdf [Accessed 17 June 2009]
Energy Exploration (2008) http://www.youtube.com/watch?v=nCnzx_xNlDE
[Accessed 15 June 2009]
Etikerentse, G. (1985) Nigerial Petroleum Law UK Macmilliam Publishers Ltd.
Drilling Practices (Oil & Gas) : Drilling Practices (Oil & Gas) Williams, T. et al (2001) Sound Coiled-Tubing Drilling Practices, Final Report Houston, Texas. U.S. Department of Energy
Thank you