Drilling Contractor Decreases Hose Costs
How a Land-Based Drilling Contractor Cut Hose Failures from 30 to One
Problem: Random Rotary Drilling Hose Failures
One of the largest land-based drilling contractors in North America kept experiencing shutdowns on their drilling rigs due to random rotary drilling hose failures. The shutdowns were compounded by long lead times to replace the hoses.
Rotary drilling hose, often called Kelly hose, carries drilling fluid from the mud pumps to the drill string. The hose runs from the top of the standpipe to the swivel, and must be flexible enough to move up and down with the traveling block. It also must withstand working pressures as high as 7,500 psi, with a tube rigorous enough to transport dense, abrasive drilling fluids. The cover takes a beating also, subjected to harsh weather, oil, chemicals, and abrasion.
These hoses are custom-built for the application, and vary in length up to 90 feet, depending on the height of the drilling rig. Due to their robust construction, with multiple layers of high tensile steel cable reinforcement, they cannot be cut to fit in the field. Ordering the precise length of hose is mandatory.
Another critical component on the rig is rotary vibrator hose, also called mud hose, which connects the vibrating mud pump manifold to the standpipe manifold on the drilling platform. Built identically to rotary drilling hose, rotary vibrator hose comes in lengths that range from 6 to 30 feet, with inside diameters of 2-1/2″ to 4″.
The drilling contractor was sourcing rotary drilling and vibrator hose from two places: an overseas hose manufacturer and a U.S. manufacturer whosehoses were built in China.Hose from the latter company often failed prematurely. Because rotary drilling/vibrator hose is vital to the drilling operation, a hose failure causes a complete rigshutdown while it’s being replaced. The overseas company had delivery lead times of 18 to 20 weeks. When the wrong length of hose is delivered, it takes another 18 to 20 weeks before a proper replacement hose arrives.
Between the hose failures and long delivery lead times, the drilling contractor kept experiencing downtime, a pricey proposition considering the high per-hour cost of drilling an oil or gas well. Being familiar with Gates hydraulic hose and power transmission belts, they asked Gates for help.
Solution: Intelligent Application and Product Efficiency
Mike Hausler, Gates District Sales Manager, and Jeff Jobe, Gates Oil & Gas Engineer, along with Clayton Williams from Motion Industries (Gates distributor), stepped in to assess the problem.
The drilling contractor was building a new, mobile land rig that could be “walked” across a drilling pad from one wellhead to another. They planned to have scores of these rigs in the field, and wanted to avoid problems with sourcing rotary/vibrator hoses, or with premature hose failures. They also wanted to standardize hose lengths to avoid ordering custom built hoses for each rig, and to make ordering replacements easier.
The first step for Gates was to take measurements. A critical component of the measurements taken by Hausler was the minimum bend radius of the hose. Initially, the drilling contractor wanted a 12-foot vibrator hose for these new rigs, which would have created too tight a bend radius, leading to premature failure. Hausler recommended moving the piping back a short distance to accommodate an 18-foot vibrator hose that would work on any part of their rig without compromising the bend radius.
Hausler, Jobe and Williams also helped the drilling contractor determine what hose ID to specify based on flow rates, what end terminations to use, and how to route the hoses to minimize abrasion and wear. When all the specifications had been determined, the drilling contractor wanted to know how long it would take to have the hoses delivered. The answer—two days—astounded them. Two days! They had been expecting weeks of lead time.
From the time that Gates began working with this drilling contractor, the hose failure rate for their fleet of 32 rigs dropped from one hose failure per day, to one hose failure per month, resulting in a dramatic decrease in hose cost and downtime.
Now Gates rotary/vibrator drilling hose is listed by part number in the drilling contractor’s catalogue. Fifteen new drilling rigs hitting the market in 2014 will be fitted with Gates rotary/vibrator drilling hose. And Gates and Motion Industries continue their visits to existing rigs already in operation to take measurements and make suggestions for improvement in their rotary/vibrator hose configurations.