OHGP OPEN HOLE GRAVEL PACK SYSTEM

For most open hole drilled in unconsolidated formation, the gravel pack is the preferred completion option. By filling the annular between screen and open hole with specially sized, high permeability gravel pack sand. The well bore is stabilized to control production of formation sand and protect screen from plugging and erosion. When performed with proper procedures and tools, open hole gravel can be highly productivity and long lasting completions.

The system is designed especially for open hole gravel pack and ensure the hole stability to be maintained during screen installation, packer setting, and gravel packing by allowing hydro-static pressure to be still maintained on the filter cake at all times. If gravel packing filter cake breaker treatment operation is necessary, it is no need for an additional trip for the operation, the system service tool can be converted back to wash down mode to allow filter cake breaker to be spotted across the whole open hole section before pulling the service tools.

The OHGP system is applicable to short and long intervals (up to over 1000 meters) with deviation range from vertical to horizontal.

Running

Washing down and running can assist in getting the assembly into position in the well bore. The system includes HST Hydraulic Setting tool, OHGP service tool, ASV Anti-Swabbing Valve, STSA Single Shifting tool, STDA Shifting tool, HDW Weight Down tool, LSA Snap locate Sealing Assemble. These tools have a pre-mature feature which can prevent the packer to be set unexpectedly, ensure well stability by maintaining hydro-static pressure on the formation at all times, prevent swabbing or surging of the formation during tool positioning and tool part movements, and allow wash down through the service tool to the end of the screen.

Packer setting

When the sand-control assembly has been ran to the desired depth and the open hole is displaced to solids-free fluid, the RHS packer is set by dropping a ball and applying pressure to the tubing. After the packer is set, over-pull 10 ton and slack down 10 ton to test the anchor, then apply pressure approximate 3500psi to tubing to release the setting tool, at last pick up 1 meter and apply pressure of 2000psi to annular to test the packer sealing. During this time, hydro-static pressure acts on the formation all the time.

Gravel packing

The OHGP system enables the gravel packing to be performed in the setdown position, eliminating tool movement due to thermal contraction and expansion, or hydraulic effects. Additionally, the FBSD provides visual surface indications for GP tool positions and the ability to capture real time bottom hole pressures throughout the entire operation.

Excess gravel and filter cake cleanup

Any remaining gravel slurry will be reversed out and measured with placing the service tool at reverse circulation position after gravel packing. Only if no any sand return, stop reverse circulation. The OHGP system service tool eliminates the need for an additional trip for posting gravel pack filter cake removal. The service tool can be converted back to the wash-down mode to allow filter cake breaker fluids to be spotted across the formation before pulling out the service tools. The service tools and wash pipe are retrieved from the well, and the production tubing is installation.

Feature

• With the functions of anti-swab and anti-surge

• Hydro-static communication to open hole at all times

• Wash-down capability during installation

• Single trip to gravel pack and filter cake clean up

• Set down capability during gravel pack operation

• Locking designing in Gravel Packing Sleeve avoid the faulty switching in the condition of service string moving up and down

Application

• Open hole single zone gravel pack

Associated tools

• RHS Recoverable Hydraulic setting hanger packer

• QC Quick Connection Joint

• DFS Flow Shoe

• OHGP service tool

• STSA Single Shifting tool

• HDW Weight Down tool

• GSH Gravel Sleeve

• APB Anti-Hydraulic Lock Seal Bore

• HST Hydraulic Setting tool

• ASV Anti- Swabbing Valve

• STDA Shifting tool

• LSA Snap locate Sealing Assemble.

Process Map