Different regulations exist in different countries for the abandonment(wells) Actions taken to ensure permanent isolation of the fluids and pressures of exposed permeable zones within a wellManmade hole drilled into the earth to produce liquids or gases, or to allow the injectionThe process of using pressure to force fluids down wells of fluids from the surface and from lower pressured zones of wells (Korre, 20112011 - A. KorreCO2CARE D1.1 International regulatory requirements on CO2 geological storage and site abandonmentsee more). The regulations may show variances, but they all serve the purpose of preventing the flow of formationA body of rock of considerable extent with distinctive characteristics that allow geologists to map, describe, and name it fluids between permeable zones and to the surface. Most of the abandonment(wells) Actions taken to ensure permanent isolation of the fluids and pressures of exposed permeable zones within a wellManmade hole drilled into the earth to produce liquids or gases, or to allow the injectionThe process of using pressure to force fluids down wells of fluids from the surface and from lower pressured zones practices require at least two barriers to prevent the flow of reservoirA subsurface body of rock with sufficient porosityMeasure for the amount of pore spaceSpace between rock or sediment grains that can contain fluids in a rock and permeabilityAbility to flow or transmit fluids through a porous solid such as rock to store and transmit fluids fluids up the wellboreThe physical hole that makes up the wellManmade hole drilled into the earth to produce liquids or gases, or to allow the injectionThe process of using pressure to force fluids down wells of fluids, it can be cased, open, or a combination of both; open means open for fluid migrationThe movement of fluids in reservoir rocks laterally between the wellbore and surrounding formations; cased means closing of the wellbore to avoid such migrationThe movement of fluids in reservoir rocks. The applications show some variations based on wellManmade hole drilled into the earth to produce liquids or gases, or to allow the injectionThe process of using pressure to force fluids down wells of fluids type, reservoirA subsurface body of rock with sufficient porosityMeasure for the amount of pore spaceSpace between rock or sediment grains that can contain fluids in a rock and permeabilityAbility to flow or transmit fluids through a porous solid such as rock to store and transmit fluids and fluid properties and environmental and safety concerns specific to the location and application. An overview can be found in Wollenweber et al., 2012.
The regulations of Alberta Energy Resources Conservation Board (ERCB, 2010 - 2010 ERCB Energy Resources Conservation BoardWell Abandonment, Directive 020see more) may serve as an example for the required abandonment(wells) Actions taken to ensure permanent isolation of the fluids and pressures of exposed permeable zones within a wellManmade hole drilled into the earth to produce liquids or gases, or to allow the injectionThe process of using pressure to force fluids down wells of fluids from the surface and from lower pressured zones procedures for three different wellManmade hole drilled into the earth to produce liquids or gases, or to allow the injectionThe process of using pressure to force fluids down wells of fluids types (Watson and Bachu, 20092009 - T.L. Watson, S. BachuEvaluation of the potential for gas and CO2 leakage along wellboressee more):
- Wells drilled and abandoned before setting casingA pipe which is inserted to stabilise the borehole of a well after it is drilled to the total depth: Any porous interval must be isolated to prevent cross flow between different zones. Also aquifers with salinities less than 4000 mg/L must be covered with cement to prevent contamination. After setting the cement plugs, the wellManmade hole drilled into the earth to produce liquids or gases, or to allow the injectionThe process of using pressure to force fluids down wells of fluids has to remain open for five days to detect if there is any leakage(in CO2Carbon dioxide storage) The escape of injected fluid from the storage formationA body of rock of considerable extent with distinctive characteristics that allow geologists to map, describe, and name it to the atmosphereThe layer of gases surrounding the earth; the gases are mainly nitrogen (78%) and oxygen (around 21%) or water column. If no leakage(in CO2Carbon dioxide storage) The escape of injected fluid from the storage formationA body of rock of considerable extent with distinctive characteristics that allow geologists to map, describe, and name it to the atmosphereThe layer of gases surrounding the earth; the gases are mainly nitrogen (78%) and oxygen (around 21%) or water column is observed, the casingA pipe which is inserted to stabilise the borehole of a well after it is drilled is cut one meter below the ground level and a cap is welded on top of the casingA pipe which is inserted to stabilise the borehole of a well after it is drilled.
- Wells drilled, cased, completed and abandoned: If the wellManmade hole drilled into the earth to produce liquids or gases, or to allow the injectionThe process of using pressure to force fluids down wells of fluids is cased and perforated for production/injectionThe process of using pressure to force fluids down wells, the applied abandonment(wells) Actions taken to ensure permanent isolation of the fluids and pressures of exposed permeable zones within a wellManmade hole drilled into the earth to produce liquids or gases, or to allow the injectionThe process of using pressure to force fluids down wells of fluids from the surface and from lower pressured zones procedures can be one or more of the following:
- setting bridge plug above perforations and capping with cement,
- performing squeeze cementing operations for the perforations with a cement retainer,
- setting cement plug across perforations.
Squeeze cementing is performed if communication behind the casingA pipe which is inserted to stabilise the borehole of a well after it is drilled is expected due to poor primary cement. Sections of wells not filled with cement must be abandoned with fluids inhibiting corrosion before abandonment(wells) Actions taken to ensure permanent isolation of the fluids and pressures of exposed permeable zones within a wellManmade hole drilled into the earth to produce liquids or gases, or to allow the injectionThe process of using pressure to force fluids down wells of fluids from the surface and from lower pressured zones. Pressure testing is required with a minimum of 7000 kPa. The wellManmade hole drilled into the earth to produce liquids or gases, or to allow the injectionThe process of using pressure to force fluids down wells of fluids must be checked for any leaks. If any leak is detected, remedial operations must be performed to stop the flow before cutting the casingA pipe which is inserted to stabilise the borehole of a well after it is drilled and abandoning the wellManmade hole drilled into the earth to produce liquids or gases, or to allow the injectionThe process of using pressure to force fluids down wells of fluids. If no leakage(in CO2Carbon dioxide storage) The escape of injected fluid from the storage formationA body of rock of considerable extent with distinctive characteristics that allow geologists to map, describe, and name it to the atmosphereThe layer of gases surrounding the earth; the gases are mainly nitrogen (78%) and oxygen (around 21%) or water column is observed, the casingA pipe which is inserted to stabilise the borehole of a well after it is drilled is cut one meter below the ground level and a cap is welded on top of the casingA pipe which is inserted to stabilise the borehole of a well after it is drilled.
- Wells drilled, cased and abandoned: If the wellManmade hole drilled into the earth to produce liquids or gases, or to allow the injectionThe process of using pressure to force fluids down wells of fluids is cased but not perforated, the abandonment(wells) Actions taken to ensure permanent isolation of the fluids and pressures of exposed permeable zones within a wellManmade hole drilled into the earth to produce liquids or gases, or to allow the injectionThe process of using pressure to force fluids down wells of fluids from the surface and from lower pressured zones procedures are the same as the previous case, without the necessity for isolating any perforations. Abandoning non-completed wells with cemented liners can be done by setting a bridge plug within 15 m above the liner top and capping it with either a minimum of 8 vertical metres of class "G" cement or with a minimum of three vertical metres of resin-based, low-permeabilityAbility to flow or transmit fluids through a porous solid such as rock gypsum cement. Instead of using a bridge plug, a cement plug can also be set across the liner top, extending from a minimum of 15 vertical metres below the liner top to a minimum of 15 vertical metres above the liner top (ERCB, 2010 - 2010 ERCB Energy Resources Conservation BoardWell Abandonment, Directive 020see more).