Well-completion means building a well for production (or injection) after various drilling operations.
It mainly entails making ready the bottom of the hollow to the specified specifications, running inside the production tubing and its associated downhole gear, in addition to perforating and stimulating as required. Sometimes, the system of jogging in and cementing the casing is also covered.
After a nicely has been drilled, must the drilling fluids be eliminated, the well might eventually close in upon itself. The casing ensures that this can no longer happen while additionally protecting the good stream from doors incumbents, like water or sand.
Lower completion (downhole completion)
It refers to the portion of the property throughout the manufacturing or injection region. The proper dressmaker has many gear and options to layout the lower completion (downhole of the entirety) consistent with the conditions of the reservoir.
Typically, the lower entirety is about across the efficient region using a liner hanger gadget, anchoring the lower final touch to the production casing string. The wide categories of lower final touch are listed below.
Barefoot completion
This kind is the most fundamental but can be an excellent desire for tough rock, multi-laterals, and underbalanced drilling. It involves leaving the productive reservoir segment with no tubular.
It correctly eliminates manipulation of the float of fluids from the formation; it doesn’t suit weaker formations which might need sand manipulation, nor for formations that need selective isolation of oil, gasoline, and water durations.
However, advances in coiled tubing and tractors mean that they can successfully produce barefoot wells.
Open hole
The manufacturing casing is ready above the zone of interest earlier than drilling the quarter. The sector is open to the best bore. In this situation, little price is generated with perforations. Log interpretation isn’t always critical. The property may be deepened without problems, and it’s far without difficulty converted to screen and liner.
However, excessive fuel and water manufacturing is hard to govern and may require common cleanouts. Also, it cannot selectively stimulate the c program language period in wireline logging services.
Open hole completion
This designation alludes to a scope of culminations where no packaging or liner is established set up across the creation zone. In equipped arrangements, the zone may be left uncovered. However, some sand control, as well as stream control implies, are normally joined.
Open hole completions have seen critical take-up as of late, and there are numerous setups frequently created to address explicit supply difficulties.
There have been various new enhancements that have upheld the achievement of open-opening completion. Moreover, they will overall be acclaimed in level wells, where cemented foundations are all the more expensive and, in reality, more inconvenient. The usual choices for open opening completions are:
Pre-holed liner
Additionally, now and again it is called a pre-bored liner. The liner is set up with different little penetrated openings, then, at that point, set across the creation zone to give wellbore soundness and a mediation course.
Pre-holed liner is regularly joined with open-opening packers, like growing elastomers, mechanical packers, or outer packaging packers, to give zonal isolation and seclusion. It is presently very regular to see a blend of the pre-holed liner, strong liner, and growing elastomer packers to give starting confinement of undesirable water or gas zones.
Different sliding sleeves can likewise be utilized related to open-opening packers to give impressive adaptability in zonal stream control for the existence of the wellbore.
This sort of completion is additionally being received in some water infusion wells, albeit these require a lot more prominent execution envelope for open-hole packers because of the extensive pressing factor and temperature changes in water injectors.
Open hole completions (in correlation with solidified lines) require a superior comprehension of arrangement harm, wellbore tidy-up, and liquid misfortune control.
A key contrast is that puncturing infiltrates through the initial 6-18 inches (15–45 cm) of arrangement around the wellbore. At the same time, open hole completions require the supply liquids to move through the entirety of filtrate-attacked zones around the wellbore and takeoff of the mud channel cake.
Many open opening completions will fuse liquid misfortune valves at the highest point of the liner to give well control while the upper fruition is run.
There is an expanding number of thoughts coming into the commercial center to broaden the choices for open hole completions; for instance, they can utilize electrical tools to activate a self-opening or self-shutting liner valve.
It may utilize this in an open completion to improve tidy up by bringing the well onto creation from the toe-end for 100 days, then, at that point, self-opening the heel-end. Inflow control gadgets and clever fulfillments are additionally introduced as open opening completion.
The pre-holed liner may give some essential control of solids creation, where the wellbore is thought to fizzle in amassed lumps of rubble, yet it isn’t regularly viewed as a sand control fulfillment.
Slotted liner
slotted liners can be chosen as an option in contrast to the pre-holed liners, some of the time as an individual inclination or setting up training on a field.
It can likewise be chosen to give a minimal expense control of sand/solids creation. The opened liner is machined with numerous longitudinal openings, for instance, 2 mm × 50 mm, spread across the length and perimeter of each joint.
Ongoing advances in laser cutting imply that opening should now be a lot less expensive to a lot more modest space widths. In some circumstances, the opened liner is presently utilized for similar usefulness as sand control screens.
Open hole sand control
It is particularly if the liner is required in the mechanism to hold back the processing of formation sand. There are several alternates of open-hole sand control; there are three famous choices: stand-alone screen, open hole gravel packs, which are also known as exterior gravel packs, where an amount of sand gravel is kept as an annulus nearby the sand control screen and flexible screens.
