Abstract: The invention relates to the completion of hydrocarbon wells using acid. It is known to create cavities in the formation using acid, which then collapse to leave a highly permeable region for production of hydrocarbons. An issue with this technique can be that the wellbore/tubing adjacent the cavity is damaged. The invention involves passing thin conduits through the formation transversely of the main wellbore, through which conduits acid is delivered to create unstable cavities at a distance from the main wellbore thereby stimulating production without risking instability of the main wellbore.

Abstract: The invention relates to the completion of hydrocarbon wells using acid. It is known to create cavities in the formation using acid, which then collapse to leave a highly permeable region for production of hydrocarbons. An issue with this technique can be that the wellbore/tubing adjacent the cavity is damaged. The invention involves passing thin conduits through the formation transversely of the main wellbore, through which conduits acid is delivered to create unstable cavities at a distance from the main wellbore thereby stimulating production without risking instability of the main wellbore.

Abstract: The invention relates to the decommissioning of hydrocarbon wells. It concerns the artificial promoting or inducing of creep in the overburden formation 3 surrounding an oil well 1, so that the formation rock 3 encroaches against the casing 5 to form a seal. This avoids the need to plug the annulus between the casing 5 and formation 3 with cement. The overburden may be caused to creep by reducing the pressure in the annulus, by applying heat to the overburden rock or by stressing the rock repeatedly to cause fatigue in the rock 3.

Abstract: The invention relates to the decommissioning of hydrocarbon wells. It concerns the artificial promoting or inducing of creep in the overburden formation 3 surrounding an oil well 1, so that the formation rock 3 encroaches against the casing 5 to form a seal. This avoids the need to plug the annulus between the casing 5 and formation 3 with cement. The overburden may be caused to creep by reducing the pressure in the annulus, by applying heat to the overburden rock or by stressing the rock repeatedly to cause fatigue in the rock 3.

Abstract: The invention relates to the decommissioning of hydrocarbon wells. It concerns the artificial promoting or inducing of creep in the overburden formation 3 surrounding an oil well 1, so that the formation rock 3 encroaches against the casing 5 to form a seal. This avoids the need to plug the annulus between the casing 5 and formation 3 with cement. The overburden may be caused to creep by reducing the pressure in the annulus, by applying heat to the overburden rock or by stressing the rock repeatedly to cause fatigue in the rock 3.