Method for determining closure of a hydraulically induced in-situ fracture
AssigneeMobil Oil Corporation
InventorsA. Wadood El-Rabaa, Connie R. Woehr
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Abstract
A subsurface formation surrounding a borehole is hydraulically fractured when a fracturing fluid is supplied down through the borehole by way of a fluid injection line from the surface of the earth. Pressure drop is measured along the injection line as fracturing fluid flows therethrough. Both fracture closure and minimum in-situ stress are determined at the point where such pressure drop is equal only to a hydrostatic pressure difference along the injection line.
Claims10
A method for monitoring the hydraulic fracturing of a subsurface formation comprising the steps of:
- a) hydraulically fracturing a subsurface formation surrounding a borehole with a fracturing fluid applied to the subsurface formation by way of a fluid injection line extending down through the borehole from the surface of the earth,
- b) measuring pressure at a pair of spaced-apart positions along the fluid injection line as fluid flows through said injection line during fracturing of the subsurface formation,
- c) shutting off the flow of fracturing fluid through the injection line to the subsurface formation, and
- d) identifying fracture closure when there is only a hydrostatic pressure difference between said pair of pressure measurements.
A method for determining fracture closure following the in-situ fracturing of a subsurface formation comprising the steps of:
- a) hydraulically fracturing a subsurface formation surrounding a borehole with a fracturing fluid applied to the subsurface formation by way of a fluid injection line extending down through the borehole from the surface of the earth,
- b) measuring pressure drop along the fluid injection line as fracturing fluid flows through said injection line during fracturing of the subsurface formation,
- c) measuring hydrostatic pressure along said injection line,
- d) shutting off the flow of fracturing fluid through said injection line to said subsurface formation, and
- e) identifying the point of fracture closure when said pressure drop along the fluid injection line is equal only to said hydrostatic pressure.
Dependencies are inferred from the claim text.