Bottom hole assembly

A bottom hole assembly for use with coiled tubing for fracturing a zone in a wellbore having a casing, comprising:

• a hollow mandrel functionally associated with the coiled tubing, the mandrel surrounded by an outer housing, the outer housing and the casing forming an annulus therebetween;
• an upper packing element;
• a lower packing element, the upper and lower packing elements disposed around the outer housing such that the packing elements are capable of straddling the zone to be fraced and are capable of setting the bottom hole assembly in the casing when the elements are set;
• an upper dump port in the outer housing, the upper dump port placing the annulus and a flow path within the hollow mandrel in fluid communication when an upward force is applied to the mandrel via the coiled tubing to deflate the upper and lower packing elements;
• and
• a timing mechanism to ensure the fluid communication continues for a predetermined time to prevent the dump port from closing before the bottom hole assembly is flushed;
• an upper pressure boost piston in fluid communication with the flow path, the annulus, and the upper inflatable packing element;
• and
• an lower pressure boost piston in fluid communication with the flow path, the annulus, and the lower inflatable packing element, the upper and lower boost pistons operating to increase the pressure inside the upper and lower packing elements.

A bottom hole assembly for use with coiled tubing for fracturing a zone in a wellbore having a casing, comprising:

• a hollow mandrel functionally associated with the coiled tubing, the mandrel surrounded by an outer housing, the outer housing and the casing forming an annulus therebetween;
• an upper packing element;
• a lower packing element, the upper and lower packing elements disposed around the outer housing such that the packing elements are capable of straddling the zone to be fraced and are capable of setting the bottom hole assembly in the casing when the elements are set;
• an upper dump port in the outer housing, the upper dump port placing the annulus and a flow oath within the hollow mandrel in fluid communication when an upward force is applied to the mandrel via the coiled tubing to deflate the upper and lower packing elements;
• a timing mechanism to ensure the fluid communication continues for a predetermined time to prevent the dump port from closing before the bottom hole assembly is flushed;
• an upper packer equalization port;
• and
• a lower packer equalization port,
• the upper and lower packer equalization ports functionally associated with an annular space between the mandrel and the outer housing to provide a fluid communication bypass from above the upper packing element to below the lower packing element.

A bottom hole assembly for use with coiled tubing for fracturing a zone in a wellbore having a casing, comprising:

• a hollow mandrel functionally associated with the coiled tubing, the mandrel surrounded by an outer housing, the outer housing and the casing forming an annulus therebetween;
• an upper packing element;
• a lower packing element, the upper and lower packing elements disposed around the outer housing such that the packing elements are capable of straddling the zone to be fraced and are capable of setting the bottom hole assembly in the casing when the elements are set;
• an upper dump port in the outer housing, the upper dump port placing the annulus and a flow path within the hollow mandrel in fluid communication when an upward force is applied to the mandrel via the coiled tubing to deflate the upper and lower packing elements;
• a timing mechanism to ensure the fluid communication continues for a predetermined time to prevent the dump port from closing before the bottom hole assembly is flushed;
• at least one orifice in the outer housing, the at least one orifice adapted to provide fluid communication through the mandrel and the outer housing so that a fracing slurry may proceed down the coiled tubing through the flow path in the hollow mandrel, and into the zone to be fraced;
• and
• at lease one flow guide, the flow guide changing the direction of the slurry from down the flow path in the hollow mandrel into the zone to be fraced.

A bottom hole assembly for use with coiled tubing for fracturing a zone in a wellbore having a casing, comprising:

• a hollow mandrel functionally associated with the coiled tubing, the mandrel surrounded by an outer housing, the outer housing and the casing forming an annulus therebetween;
• an upper packing element;
• a lower packing element, the upper and lower packing elements disposed around the outer housing such that the packing elements are capable of straddling the zone to be fraced and are capable of setting the bottom hole assembly in the casing when the elements are set;
• an upper dump port in the outer housing, the upper dump port placing the annulus and a flow path within the hollow mandrel in fluid communication when an upward force is applied to the mandrel via the coiled tubing to deflate the upper and lower packing elements;
• a timing mechanism to ensure the fluid communication continues for a predetermined time to prevent the dump port from closing before the bottom hole assembly is flushed;
• and
• a delay mechanism to prevent the packing elements from becoming instantaneously unset when the upward force is applied to the mandrel.

A method of fracing a zone in a wellbore having a casing using coiled tubing, comprising:

• providing a bottom hole assembly having
• a hollow mandrel functionally associated with the coiled tubing, the mandrel surrounded by an outer housing, the outer housing and the casing forming an annulus therebetween,
• an upper packing element,
• a lower packing element, the upper and lower packing elements disposed around the outer housing such that the packing elements are capable of straddling the zone to be fraced and are capable of setting the bottom hole assembly in the casing when the elements are set,
• an upper dump port in the outer housing, the upper dump port placing the annulus and a flow path within the hollow mandrel in fluid communication when an upward force is applied to the mandrel via the coiled tubing to unset the upper and lower packing elements, and
• a timing mechanism to ensure the fluid communication continues for a predetermined time to prevent the upper dump port from closing before the bottom hole assembly is flushed;
• running the bottom hole assembly into the casing such that the packing elements straddle the zone to be fraced;
• setting the upper and lower packing elements by increasing the flow through the flow path in the mandrel;
• fracing the zone;
• applying an upward force on the coiled tubing to unset the packing elements;
• flushing the bottom hole assembly before resetting the packing elements;
• providing a release tool having a release tool to connect the hollow mandrel with the coiled tubing, the release tool having a reset mechanism adapted to allow a user to attempt to dislodge the bottom hole assembly when the bottom hole assembly is lodged in the casing, without releasing the bottom hole assembly from the coiled wire tubing;
• applying a predetermined force to the release tool via the coiled tubing to attempt to release the bottom hole assembly when the bottom hole assembly is lodged in the casing;
• and
• resetting the release tool to its original position once the upward force is no longer applied to the coiled tubing.