Flow loop testing center develops innovative practices

With the amount of innovative technology deployed in today’s oil fields, performance levels often are pushed to extremes. Knowing how equipment will function under specific conditions present in the field is paramount to successful oil and gas operations. One way to assure the highest level of integrity for downhole equipment is to push tools to extremes in the confines of the laboratory.

Simulating real-world conditions in a controlled environment is challenging. A driver in the R&D field is to understand how tools will function during actual operations. To meet the challenge, manufacturing companies must find ways to mirror the conditions their tools and equipment will discover on the job.

Top-Co’s engineering team is focused on the R&D of new products, often in response to operating challenges encountered by customers. The engineering team, populated with professionals with experience in this sector, employs electronic design media and 3-D modeling to facilitate precise and quick designs. In-house testing validates new or improved products prior to field introduction. Upgraded state-of-the-art test loop equipment currently is being installed, ensuring that existing and modified float equipment consistently complies with API IIIC specifications.

Commissioned in 2009, Top-Co’s flow loop testing facility is designed to foster standard and creative testing for a number of its tools. In addition, a goal has been to close the cycle from identifying a product requirement to achieving complete customer satisfaction.

Top-Co’s facility features a tank with a storage capacity of 160 bbl and has two agitators used in combination with the tank’s shape to avoid sagging of the weighting material in the drilling mud. Mud is pumped with a centrifugal pump capable of delivering up to 22 bbl/minute at approximately 140 psi. Heat blankets in the pipes can be set to 600 ºF while circulating the mud to increase its temperature to the test requirements. (Images courtesy of Top-Co Primary Cementing Equipment)

The facility benefits from a centralized design allowing all testing to be conducted in the same physical location. Benefits of this centralized design concept include:
• Systematic execution of a comprehensive test matrix;
• Development and maintenance of a central test results database;
• Standardization of test procedures;
• Testing in a clean, organized, and controlled environment; and
• Ease of implementation of a 6S philosophy in the test facility.

The facility’s flexibility and capabilities cater to all areas of top-rated testing programs, including R&D (new product development and existing product improvement), quality control, process verification, and failure analysis or third-party testing. The facility also doubles as a training center for customers and personnel.

The layout
The main part of the facility is the flow loop, which consists of a tank and pumps room along with a test bench.

The tank has a storage capacity of 160 bbl and has two agitators used in combination with the tank’s shape to avoid sagging of the weighting material in the drilling mud.

Mud is pumped with a centrifugal pump capable of delivering up to 22 bbl/minute at approximately 140 psi. Heat blankets in the pipes can be set to 600 ºF (316ºC) while circulating the mud to increase its temperature to the test requirements.

The flow rate is measured continuously by a flowmeter installed at the exit of the test bench and is controlled by varying the speed of the centrifugal pump. The flow loop has three thermometers measuring mud temperature. One is installed in the tank and is used mainly during mud warmup prior to starting a test. The other two are installed in the inlet and outlet of the test bench and allow for full compliance with test temperature requirements by API RP 10F, independently of heat loss due to a lower ambient temperature.

A second triplex positive displacement water pump capable of delivering up to 5 gal/minute at 5,000 psi also is installed.
The specifications allow for testing beyond the conditions described in API Recommended Practice 10F “Recommended Practice for Performance Testing of Cementing Float Equipment.” The facility allows for simultaneous testing of up to four test specimens.

The flow rate is measured continuously by a flowmeter installed at the exit of the test bench and is controlled by varying the speed of the centrifugal pump. The pump’s motor speed is, in turn, controlled by a variable frequency drive that reacts to the flowmeter’s measurement, adjusting the pump speed as required to maintain the specified flow rate. This setup allows for a stable constant flow rate to be maintained during testing.

The flow loop has three thermometers measuring mud temperature. One is installed in the tank and is used mainly during mud warmup prior to starting a test. The other two are installed in the inlet and outlet of the test bench and allow for full compliance with test temperature requirements by API RP 10F, independently of heat loss due to a lower ambient temperature. This is of importance during tests conducted in winter.

A parameter in the testing of float equipment is what API calls “volume required to achieve valve closure,” which the facility can accurately measure by collecting backflow in graduated buckets sitting on calibrated weight scales. The weight measurement is used in combination with the latest rheological properties to calculate the volume. The combination of leak weight and visual observation allows the operator to identify minimum amounts of backflow (dripping). In a real application, a valve leaking a very small amount could go undetected for days or weeks when the plug is found higher than expected.

The flow loop is equipped with 22 pressure measurement locations connected to a data acquisition system capable of recording up to 100 readings/second. A benefit of this system is the flexibility in the types of tests it allows, in addition to standard API tests. All instruments in the facility are subject to a strict calibration schedule that also is part of the plant’s quality management system.

The facility’s pumps and valves are actuated from the control software, allowing for a complete test to be run entirely from the computer. To minimize operator impact on the test results, an investment was made to build subroutines into the software that guide the operator through the test procedure. This improves the speed at which tests are conducted and increases the repeatability of results.

The facility also has a high-pressure, high-temperature test chamber capable of operating above 400ºF (204ºC) and 10,000 psi. Additionally, simulating annular pressure also is possible.

Recently, live web broadcasting capabilities were added, allowing tests to be witnessed and discussed with Top-Co’s customers. This manufacturer-user interaction has played an important role in recent product developments. The webcams also are used for giving virtual tours of the facility to customers unable to visit the plant in Edmonton.

Testing: API and beyond
Top-Co’s testing is capable of testing fluids and equipment by the book, as outlined in API standards, but it also maintains flexibility for generating innovative new testing methods.

The flexibility built into the facility has allowed for testing beyond standard test procedures. For example, extensive testing was conducted to determine the effect of orientation and inclination on valve performance.

In anticipation of the longer reach and deeper wells in the coming years, Top-Co also has initiated tests under more demanding conditions such as higher flow rates and longer circulating times. This is most relevant in extended-reach wells, where fluid particle velocities required for appropriate hole cleaning may be as high as three to five times those of vertical wells and take longer to clean. For deeper wells, higher differential pressure capabilities may be expected and, therefore, testing above 5,000 psi also is required. Top-Co is using this capability in testing on destruction and development of new high-pressure products.

The facility has provided a more efficient path -- from identifying product requirements to designing and testing them to improving them and, finally, achieving customer satisfaction.