Cochrane Technologies, Inc. is in the process of field-testing the first generation production model of a simple, effective, and modestly priced device that will accurately indicate when a pipeline of any size has touched the sea bottom. The touchdown indication is activated by a specially designed switch, which gives a contact closure to indicate when the pipe is horizontal to the ocean floor. Because the device is secured to the pipe, there is no concern as to whether there is a void directly under the pipe as there would be when using a contact type switch.

The Pipeline Touchdown Indicator consists of a watertight capsule, which is strapped or connected securely to the pipe as it leaves the pipe sled and is connected by a small 2 pair cable to a handheld Power/ Indicator Module on shipboard. The cable is fed from an easy feed reel. The Power/ Indicator Module indicates:

• Whether the cable integrity is good or bad by a red or green LED.
  • If the cable breaks, a cable fault circuit will not allow any inaccurate readings and the Touchdown Indicator LED will never light.
• Actual Touchdown by a green LED and a Loud Buzzer.

The length of the connecting cable has been tested to operate past 2500 feet of length and when the underwater capsule is secured to the pipe, so as not to float, it is good to well past 1000 feet of water depth. Deeper depths would require minor modifications at modest cost. The Power/ Indicator Module can easily be modified to remote an indicator light and alarm and can be custom packaged. The underwater capsule is inexpensive and not normally recovered, but the Power/ Indicator Module is reusable. The power module operates from 12 VDC, using either a small AC supply or a lantern battery.

Click to enlarge image

Cochrane Technologies, Inc. is pleased to announce the availability of an electronic device to very accurately measure the length of pipe laid from a Lay Barge. Pipelines from 2" to 42" in diameter are supported using the prototype device and larger sizes are possible. The very accurate measuring system uses an encoder connected to a positive contact rotating wheel with resolution to one inch. The encoder output is fed by short data cable to an electronic counter scaled to read 1-foot increments. Absolute accuracy of length measurement is much better than 5 feet per mile (.1 % or better). The measurement data is converted to a standard RS 232 data string and transmitted by a Radio Data Link to one or more points of interest where it can be viewed simply as an elapsed distance in feet or applied to a navigation program for more complex systems integration. The encoder and counter respond to and keep accurate track of bi-directional movement of the pipe--- pipe moving off the barge is a positive count and any motion of the pipe toward the Barge bow is a negative count, with movement of as little as 1" accurately added or subtracted.

Designed at Cochrane's ONI Subsidiary in Slidell, LA, staffed by personnel with over 75 years of offshore experience, the Pipeline Measuring Device (Tally Wheel Counter) is a dependable, versatile and durable machine built to survive the harsh offshore environment. The counting system operates using a nominal 13.6 volt DC power supplied by a 117 V AC to 13.6V DC power supply. A battery provides backup power to operate the counting system for more than 12 hours if AC power is lost. The Radio Data Link operates on 117 V AC so that loss of Data will act as an alert if AC power is lost, allowing restoration of lost AC power. The counter also has an 8-year memory battery to retain setup and last count data. There is the very necessary capability of presetting the "Start" count, which could be a number other than zero. This feature will also allow the count to be restored if the pipe has to be disconnected and laid on the bottom because of weather, or for any other occasion that may interrupt the count. All electronic equipment is mounted inside a weather proof housing (a stainless box with a hinged lid on production models). All command control of electronics will be accomplished by the Data Radio Link, allowing the wheel/ counter assembly to be unmanned most of the time.

It is likely that mounting requirements will vary some from one Lay Barge to another. The measuring wheel and electronics can easily be adapted to virtually any mounting challenge. The prototype is designed with the wheel mounted on an "Inverted L" framework to be mounted on a plate welded to the barge deck. The mounting frame has the capability of being raised or lowered to accommodate various pipe sizes and also the ability to swing the measuring wheel 90 degrees to the port or starboard off the top of the pipe. The wheel is mounted above the pipe, and the weight of the wheel/ encoder assembly (about 90 pounds) will hold it in firm contact with the pipe. The wheel assembly will be centered over the pipe during installation and positioned forward of its mount in a "vertically floating arm" arrangement to make contact with the pipe at an angle of 30 to 60 degrees to the vertical. Because of the durable construction of the measuring wheel contact surface, no degrading of accuracy will occur from surface wear for many months or years of use. Also, because of the 1" resolution of the wheel encoder no "slippage of count" will occur as a result of back and forth movement of the pipe.

Cochrane Technologies, Inc. of Lafayette, Louisiana, USA has recently accepted delivery of another Sonardyne’s Programmable Acoustic Navigator (PAN). Sonardyne’s Programmable Acoustic Navigator (PAN) is a microcomputer-controlled unit dedicated to the transmission, reception, and decoding of acoustic signals. It is part of Sonardyne’s integrated family of underwater acoustic navigation and telemetry equipment.

The system is applicable to a wide range of tasks in underwater engineering measurement, remote control, and monitoring. This equipment, when operated in medium frequency, provides the best compromise between long range, accurate positioning and operation in high-level noise. When operating in the low-frequency band, with low-frequency COMPATTs, ranges of over 10 km are obtainable. When working with an extra high-frequency, the COMPATT’s accuracies of 30 mm or better can be achieved.

Cochrane Technologies, Inc. plans to use the PAN as a deepwater survey tool to assist in deep water construction activities including pipelay projects, template orientations, and jacket installations. The COMPATTs are deployed on the sea floor in a geometric array, and the PAN is used in conjunction with surface positioning to translate geodetic positions to the seafloor. Once calibrated, the geodetically positioned COMPATTs can then measure ranges to accurately determine the position of a COMPATT placed on the structure being installed.

Cochrane Technologies, Inc., has been a leader in Oil & Gas underwater acoustic surveys since 1980, and offers a wide variety of state-of-the-art systems to map seafloor locations, locate debris, and recover objects lost overboard.

Cochrane Technologies, Inc. (C.T.I.) has purchased (2) two of Kongsberg Simrad Mesotech’s new MS 1000 Digital Bottom Scanning Sonar Units from C.A. Richard’s & Associates Inc. CTI was involved in the design with Kongsberg of several key features of this new SONAR and performed field testing in the Gulf of Mexico. These systems offer state of the art technology like a newly designed high resolution digital sonar head capable of operating in 1000 meter water depths.

Digital data file storage and playback, user annotation, target measurement, and photo quality printing of images back the quality C.T.I. and our customers expect. By working in concert with equipment manufactures, CTI is able to offer “Customized Value Solutions” to our Gulf of Mexico oil & gas customers. This approach is far better than using the traditional approach of simply applying generic equipment to the specific needs of our customers.

Working with Diamond Services, Inc. of Amelia, La and Torch, Inc. of Gretna, La, Cochrane Technologies, Inc. recently completed survey services for the installation of nine pipelines in the South Pelto area. All pipelines linked South Pelto Block 5 “B” Structure of Bois d’Arc Offshore LTD with new wells and transmission lines in the area.

Cochrane Technologies, Inc. provided surveying services for Offshore Specialty Fabricators, Inc. to install a new United States Coast Guard Aids to Navigation Light Tower and remove the old structure at the junction of 6 Shipping Fairways approaching New York Harbor.

U.S.C.G. specifications for the installation required that the light on the three-legged structure be installed within 25’ of the proposed location and placed on a specific orientation. Cochrane Technologies, Inc. accomplished the installation phase using Differential GPS techniques and a precise gyrocompass broadcasting data via a radio link to the master computer on board the construction barge. On board the barge, key personnel were able to view and direct the installation process while viewing the display screen of Cochrane Technologies, Inc. navigation software CNAV. CNAV portrayed a scaled image of the structure in real time position in relation to an identical “ghost image” or template of the structure shown on proposed location and orientation. This setup allowed the installation supervisor to direct the installation process by aligning the real time image over the template.

U.S.C.G. specifications also required completion of a precise final survey of the three dimensional position of the structure using Real Time Kinematic GPS techniques. Review of these specifications identified that Real Time Kinematic GPS techniques could not meet the required accuracies and Cochrane Technologies, Inc. personnel proposed that a precise Static GPS survey in conjunction with a Very Short Term Tide Study be performed instead. U.S.C.G. officials approved the proposal and the final survey was completed shortly after installation was completed. The results of the Static GPS survey confirmed the light to be 6.74 feet from the proposed location and well within the 25 feet specification by the United States Coast Guard.

Cochrane Technologies, Inc., contracted to Diamond Services Corporation of Amelia, La., recently completed surveying services for the installation of the Southwest Pass Leading Light Structure for the United States Coast Guard. This structure serves as a navigation aid for shipping traffic approaching the mouth of Southwest Pass on the Mississippi River in Plaquemines Parish, Louisiana.

United States Coast Guard specifications for this project required the structure to be placed within 1 foot perpendicular to the centerline of the channel and 10 feet of proposed position parallel to the centerline of the channel and meet Third Order Class 1 survey specifications. Review of these specifications identified that Differential GPS survey techniques commonly used for work in the Gulf of Mexico would not meet project specifications.

To meet specifications, Cochrane Technologies, Inc. personnel recovered NGS geodetic control monuments along Southwest Pass and ran a traverse using conventional surveying techniques to establish control at the mouth of Southwest Pass. Conventional Total Station theodolites on the established control were used to track a 360° prism mounted on the structure during installation. The Total Stations provided a continuous readout of the horizontal angle, zenith angle, and slope distance between control station and prism target. This data was broadcast via a radio link to Cochrane Technologies, Inc. proprietary navigation software C-NAV which provided installation personnel with a real-time onscreen representation of the position of the structure in relation to the proposed position. The final position of the structure was 0.44’ perpendicular to channel centerline and 1.59’ from proposed parallel to centerline.

Cochrane Technologies, Inc. (CTI) of Lafayette, Louisiana has deployed a new derivative of the Kongsberg Simrad Mesotech Ltd. (KSML) 1071 digital sonar head for bottom clearance surveys in the Gulf of Mexico with outstanding results. With this success, COCHRANE has ordered additional 1071 systems.

This latest version of the 1071 digital sonar head is used in conjunction with the MS 1000 digital sonar processor. The 'High Resolution' 675 kHz unit has a significantly wider receiver bandwidth coupled with a new 0.89 degree transducer, resulting in images with much finer resolution.

"The MS 1000 is the finest Scanning Sonar we have ever used," said Dwayne Truesdell, Vice President of Operations for COCHRANE. "KSML and COCHRANE deployed the first Bottom Scanning Sonar applications in the Gulf of Mexico over a decade ago. Today, this strategic relationship offers the latest sonar technology available. The key to our success is the support and service provided by KSML. It's not often that someone can actually talk to the person who designed the product. KSML's Mark Atherton came here, listened to our ideas, went offshore with us and we beta tested the new sonar together."

"This 'High Resolution' version of the 1071 digital sonar head was designed to meet the exacting needs of offshore oil exploration and is a significant upgrade," said Hans Gray, KSML President.

The sonar heads COCHRANE is using are prototypes. Production versions will be available in summer 2000.