At the end of this presentation, you will be able to:
•Factors influencing completion design.
•List and define the different types of completion
•Describe surface control equipments
•Define subsea completion
Introduction to Well Completions
• After exploratory drilling confirms the presence of an oil or natural gas
reservoir, the hydrocarbons are brought to the surface.
• Once the design well depth is reached, the formation is tested and
evaluated to determine whether the well is to be completed for
production, or plugged and abandoned.
• This decision is taken based on the information available on reservoir
• To complete the well production, casing is installed and cemented, and
the drilling rig is dismantled and moved to the next site.
• A service rig is brought in to perforate the production casing and run
production tubing along with down hole equipments.
• The installation of surface safety equipments takes place and
13 3/8’’ CASING
Production casing (9 5/8)
It’s a link between drilling the borehole and
the production phase.
Well completion creates a dependable pathway
to the surface for the hydrocarbons.
Once the well is drilled, it has to be made ready
for the safe and efficient production of oil.
The term ‘completion’ describes the assembly of
Down hole tubulars and other safety equipments
that is required to enable the safe and efficient
production of oil or gas from the well after it has
What is Completion?
Purpose of the well
• Exploration wells: To obtain preliminary data on a reservoir, nature and
characteristics of the fluids on the reservoir, pay zone characteristics (pressure,
temperature, permeability and productivity)
• Appraisal or confirmation: Refine or complete the data from exploration and
determine the off-wellbore characteristics (permeability, reservoir boundaries,
existence of faults/discontinuity)
• Developmental well: This stage brings the wells on the production stream.
Assess well conditions and effectiveness of completions and obtain further info
on the well.
– Production- productivity
– Injection- Optimize reservoir pressure
– Observation-monitor variations in reservoir parameters
Parameters related to the Environment
• Constrains related to country/site/location of well
i.e land or offshore.
• Environmental restrictions involve:
– Difficulty in obtaining supplies
– Available space
– Available utilities
– Safety rules and regulations
– Certain operations that may or may not be possible
Meteorological and oceanographic conditions must also be taken into
consideration where applicable.
Parameters related to the Drilling
• Types of rigs
• Well profile-
• Drilling and casing program
• Drilling in the pay zone(s) and
drilling fluids- formation
damage and fluid
• Cementing the production
Parameters related to the Reservoir
• Reservoir pressure and its changes-
need for injection wells?
• Interface between fluids and their
changes- water encroachment
• Number of levels to be produced
• Rock characteristics and fluid types
• Production profile and the number of
Parameters related to the Production
• Safety- compliance with various regulations
• Flowing well or artificial lift- a wells flow capability depends on
natural changes in bottom hole pressure versus cumulative
• Operating conditions- space availability, operating fluids-
• Anticipated measurement, maintenance or work over operations-
maintenance and repair operations to ensure the well reaches its
• Parameters related to completion
techniques: general configuration, pay zone to bore hole
connection, treatment of the formation, equipment installed,
• Synthesis-How completion is designed-
completions should be designed to optimize
productivity/injectivity performance, make sure the well produces
reliably and safely, optimize the implemantation of atrificial lift,
optimize equipment lifetime and make it easy o change all or some
of the equipment in the future without much difficulty.