Guide Shoes Information
Guide shoes are bull-nose devices that attach to the bottom of the casing string. They protect the casing string from impact, enable passage through narrow or deviated boreholes, and direct away from ledges reducing the chance of sidewall cave-in during casing running operations. Guide shoes are typically manufactured from heavy steel and have rounded profiles to guide the casing string through the wellbore. The bull nose end incorporates an open end or side ports to enable circulation of well bore fluids and cement slurries.
Casing is a large diameter pipe used to line the walls of a well bore. Sections of casing are joined at the rig floor as they are lowered into the well. The guide shoe is connected to the end of the first casing string in order to maneuver the casing past annular irregularities. To learn more about casing please visit Engineering360’s casing specification guide (here).
Standard guide shoes have a single large diameter open hole through the center of the shoe. While the open hole allows for fluids displacement the guide shoe primarily acts to protect the casing string. They allow safe passage through narrow, deviated holes and areas with hard shoulders.
Down-Jet guide shoes incorporate additional side ports in the steel case. These additional ports allow for a jetting action that helps remove wellbore cuttings. They also produce a turbulent flow regime when fluid is pumped through the device, which improves cement distribution during cementing operations.
Float shoes are guide shoes that incorporate a check valve. They function both as a guide shoe and as a piece of floatation equipment. The integral check valve helps float the casing string into position during case running operations as well bore fluids are displaced up through the annulus. The valve then acts to prevent reverse flow or u-tubing of cement slurry during cementing operations.
API RP 10F — Recommended testing practices to evaluate the performance of cementing float equipment for the petroleum and natural gas industries.
API SPEC Q1 — Minimum quality management system requirements for organizations that manufacture products or provide manufacturing-related processes under a product specification for use in the petroleum and natural gas industry.