Completion, in petroleum production, is the process of making a well ready for production (or . Proper design of this "completion string" is essential to ensure the well can flow properly given the reservoir conditions and to permit any operations. Production Technology and Stimulation Well Completion Design & Practices. Course book based on course well completion design by TRACS International* Unique in its field: Coverage of offshore, subsea, and.
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Lower completion[ edit ] Well completion design refers to the portion of the well across the production or injection zone. The well designer has many tools and options available to design the lower completion according to the conditions of the reservoir.
Typically, the lower completion is set across the productive zone using a liner hanger system, which anchors the lower completion to the production casing string.
Completion systems -
The broad categories of lower completion are listed below. Barefoot completion[ edit ] This type well completion design the most basic, but can be a good choice for hard rock, multi-laterals and underbalance drilling.
It involves leaving the productive reservoir section without any tubulars. This effectively removes control of flow of fluids from the formation; it is not suitable for weaker formations which might require sand control, nor for formations requiring selective isolation of oil, gas and water intervals.
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However, advances in interventions such as coiled tubing and well completion design means that barefoot wells can be successfully produced. Open Hole[ edit ] The production casing is set above the zone of interest before drilling the zone. The zone is open to the well bore.
In this case little expense well completion design generated with perforations log interpretation is not critical.
The well can be deepened easily and it is easily converted well completion design screen and liner. However, excessive gas and water production is difficult to control, and may require frequent clean outs.
Also the interval can not be selectively stimulated.
Petrel Well & Completion Design
Open hole completion[ edit ] This designation refers to a range of completions well completion design no casing or liner is cemented in place across the production zone. Openhole completions have seen significant uptake in recent years, and there are many configurations, often developed to address specific reservoir challenges.
There have been many well completion design developments that have boosted the success of openhole completions, and they also tend to be popular in horizontal wells, where cemented installations are more expensive and technically more difficult.
The common options for openhole completions are: Pre-holed liner[ edit ] Also often called pre-drilled liner.
The liner is prepared with multiple small drilled holes, then set across the production zone to provide wellbore stability and an intervention conduit.
Well Completion Design (Drilling and Well Completion): IPIMS e-Learning
well completion design Pre-holed liner is often combined with openhole packers, such as swelling elastomers, mechanical packers or external casing packers, to provide zonal segregation and isolation. Multiple sliding sleeves can also be used in conjunction with openhole packers to provide considerable flexibility in zonal flow control for the life of the wellbore.
This type of completion is also being adopted in some water injection wells, although these require a much greater performance envelope for well completion design packers, due to the considerable pressure and temperature changes that occur in water injectors.
Openhole completions in comparison with cemented pipe require better understanding of formation damage, wellbore clean-up and fluid loss control. Many openhole completions will incorporate fluid loss valves at the top of the liner to provide well control whilst the upper completion is run.
There are an increasing number of ideas coming into the market place to extend the options for openhole completions; for example, electronics can be used to actuate a self-opening or self-closing liner valve.
This might be used in an openhole completion to improve clean-up, by bringing the well onto production from the toe-end for days, then self-opening the heel-end. Inflow control devices and intelligent completions are also installed as openhole completions. Pre-holed liner may provide some basic control of solids production, where the wellbore is thought to fail in aggregated chunks of rubble, but it is not typically regarded as a well completion design control completion.
Slotted liner[ edit ] Slotted liners can be selected as an alternative to pre-holed liner, sometimes as a personal preference or from established practice on a field. Recent advances in laser cutting means that slotting can now be done much cheaper to much smaller slot widths and in some situation slotted liner is now used for the same functionality as sand control screens.
Openhole sand control[ edit ] This is selected where the liner is required to mechanically hold back the movement of formation sand. There are many variants of openhole sand control, the three popular choices being stand-alone screens, openhole gravel packs also known as external gravel packs, where a sized sand 'gravel' is placed as an annulus around the sand control screen and expandable screens.
Screen designs are mainly wire-wrap or premium; wire-wrap screens use spiral-welded corrosion-resistant wire wrapped around a drilled basepipe to provide a consistent small helical gap such as 0.
Premium well completion design use a woven metal cloth wrapped around a basepipe.