Research and Development
Top-Co as a manufacturer of primary cementing equipment relies on the contributions that state-of –the art technology to mature and innovative testing practices provides.
Top-Co’s state-of-the-art flow loop test facility allows us to offer high quality products through dynamic testing of equipment. In addition to verifying product performance, the facility provides empirical input for our continuous improvement program.
The Flow Loop Test Facility includes:
- State-of-the-art Flow Loop
- High pressure / high temperature test chamber
- Centralizer test bench
- Cement compression strength test cell
- Maximum flow rate of 22 bpm (through a 4″ flow diameter)
- Maximum static pressure capability of 5,000 psi
High pressure / high temperature test chamber
- The maximum working temperature is 500°F (260°C) at a maximum working pressure of 15,000 psi (103 MPa)
- The fixture is equipped with three temperature probes for measuring both internal and external temperature of float equipment during testing process
Centralizer test bench
- Maximum working diameter of 36” (centralizers)
- Maximum load force of 50,000 lb
- Maximum cylinder stroke of 36”
BENEFITS TO OUR CUSTOMER:
- New product designs fully tested before introduction to marketplace
- Confirmation of consistency in product performance
- Quality control
- Custom testing on any test specimen that fits between the working areas of the flow loop
- Auxiliary inputs available for alternate pressure recording
More on Flow Loop
The integral portion of the facility is the flow loop, shown in the left area of the floor plan depicted on the left. The flow loop consists of a tank and pumps room and a test bench.
The advantages of this centralized concept are:
- 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
Ease of implementation of a 6S philosophy in the test facility
Ease of implementation of a 6S philosophy in the test facility.
The facility’s flexibility and capabilities allow the execution of all areas of Top-Co’s testing program:
R&D: new product development and existing product improvement.
- Quality control
- Process verification
- Failure analysis, or third party testing
- Customer and personnel training
- Technical customer support
The picture below shows the flow loop’s tank and pumps. The tank with a storage capacity of 160 bbls contains two agitators that in conjunction with the tank’s shape avoid sagging of the weighting material in the drilling mud.
Mud is pumped with a centrifugal pump capable of delivering up to 22 bpm at approximately up to 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.
A second triplex positive displacement water pump capable of delivering up to 5 gpm at 5000 psi is also installed. As shown in the following table, these specifications allows for testing beyond the conditions described in API Recommended Practice 10F Recommended Practice for Performance Testing of Cementing Float Equipment.
The picture below shows the flow loop’s test bench. The facility allows for simultaneous testing of up to four test specimens.
The flow rate is continuously measured by a flow meter installed at the exit of the test bench (installed vertically on the right side 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 flow meter’s measurement, adjusting the pump speed as required to maintain the specified flow rate. This set-up 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 warm-up 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 significant importance during tests conducted in the cold winter season.
A key parameter in the testing of float equipment is what API calls “volume required to achieve valve closure”. The facility can accurately measure the volume by collecting any back flow in graduated buckets sitting on calibrated weight scales, as shown in the picture above. The weight measurement is used in combination with the latest rheological properties to calculate stated volume. The combination of the leak weight and visual observation allows the operator to identify even minimum amounts of back flow (dripping.) This is of most importance because in a real application there is a risk that a valve that is leaking a very small amount does not get detected immediately, but rather days or weeks later 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 per second.
The benefit of this system is the great flexibility in the type of tests that may be conducted, in addition to the standard API tests. For example, testing the performance of a stage tool requires a fast acquisition rate as to not miss the actual opening or closing pressures.
This is explained in more detail later in this document. All instruments in the facility are subject to a strict calibration schedule that is also part of the plant’s Quality Management System.
The facility’s pumps and valves are actuated from the control software, allowing for complete test to be run entirely from the computer. To minimize the impact of the operator on the test results, a significant investment was done 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 their results.
The facility also includes a high pressure, high temperature test chamber capable of operating above 400ºF and 10,000 psi. Additionally, simulating annular pressure is also possible.
As it may be apparent from the description presented above, management of the facility and more importantly, of the testing program is essential to be able to benefit from the large amount of data generated. A strategy and system were designed and implemented to schedule, prepare, execute, and grade each test and provide feedback to engineering. A central test results database for all product types was built that allows for both quantitative and qualitative analysis. The management system also includes preventive maintenance and inventory control.
Another benefit the facility has provided is the capability of executing tests “by the book” exactly as described in the corresponding API or other test procedures.
API RP10F describes three test categories consisting of a number (I, II, or III) and a letter (A, B, or C.)
The number is an indication of the durability flow test. This test consists of flowing mud through the valve for two hours and then performing a back pressure test to confirm the valve closes and completely seals. This cycle or flow and back pressure application is repeated until the total test duration is completed, which can be up to a total of 24 hrs. The last part of the test calls for a final back pressure test conducted at high pressure and for 30 minutes. A summary of the durability test categories is shown in the picture below.
During the entire duration of the test, the facilities control and data acquisition system continuously measures and records relevant test parameters as illustrated in the following flow and back pressure graphs:
Every two hours the rheological properties of the drilling mud are measured to confirm they are within API specifications:
- Density: 12 – 12.5 lb/gal
- Plastic Viscosity: 10 – 50 cp
- Yield Point : 5 – 25 LB/100 sq ft
- 10-s gel Strength: > 4 lb/100 sq ft
- Sand Content: 2 – 4 percent by volume of 70/200 mesh sand
- Properties at 120° Fahrenheit.
Upon completion of the durability test as described above, the test piece is removed from the flow loop and inspected for signs of abnormal wear or performance. The second part of the test consists of a high pressure, high temperature test in which the test piece is soaked at up to up to 400ºF for eight hours and then back pressure is applied in 500 psi increments from zero up to 5,000 psi, holding each one for 15 minutes and confirming the valve is not leaking.
As in the durability test, pressure and temperature is continuously measured and monitored during the entire duration of the test:
Beyond API Tests
Furthermore, 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 that the industry will pursue in the coming years, Top-Co has also 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 3-5 times those of vertical wells and which will take longer to clean. For deeper wells, higher differential pressure capabilities may be expected and therefore testing above 5000 psi is also required. Top-Co is using this capability in testing to destruction and developing new high pressure products.
Top-Co’s testing procedure for differential fill valves is another example of going beyond standard procedures. In addition to following the steps indicated in API RP 10F for differential fill equipment, the flow loop’s flexibility also allows for testing the differential action of this type of valves.
Similarly, generating performance curves of pressure drop vs. flow rates has also become a common practice at Top-Co. This information is available to our customers and can be used for more accurate surge and swab calculations.
Top-Co’s in house testing program is complemented with specific tests performed outside of our facility. Recently, drillout tests on three types of products were performed at a leading manufacturer’s facilities in the US. The information collected was used to confirm operating procedures as well as further product development.
Additionally, field tests are commonly performed.