|Performances of HRG gyro unit:
The main parts of three-component HGR
Application field: oil-and-gas industry
The use of HRG is accounted for by the need in highly accurate information: well trajectory measurement (during and at the end of drilling).
It is necessary to calculate drilling trajectory so that the operator could take into consideration the rotation of the Earth, which naturally accompanies the drilling process. Without such calculations the drill can deviate from the vertical axis.
In oil-and-gas industry two classes of trajectory determination sensors are used.
Magnetic sensors provide the data on jackbit trajectory to the block that calculates the parameters in the process of drilling. Magnetic sensors are cheap and have a longer lifetime than the elements they are usually replaced by. But their main disadvantage is that because of the influence of the Earth magnetic field these sensors can give wrong information.
Wrong information can cause deviation of the drilling trajectory or very slow oil production with numerous pauses for measurements.
Fibre-optic and ring laser gyros are used instead of magnetic sensors or together with them.
Many research companies such as “Scientific Drilling”, “Geoservices” and others, employed as third parties by such companies as “Hallibirton” and “Schlumberger” to confirm magnetic sensors data, take data on drilling trajectory and direction by means of dipping the gyro into the well on a cable. Such services provided by leading service companies cost about $ 5.000. Therefore oil-and-gas companies tend to make measurements themselves in order to economize their capital and time spent on delivery of specialists to the place of survey.
Magnetic sensors application in spheres where the method of making measurements is used in the process of drilling is accounted for by their ability to operate in severe conditions where high shock, vibro - and temperature resistance are required. Magnetic sensors application in suspended wells is impossible because of the Earth magnetic field influence.
High-tech gyros, mainly fibre-optic and ring laser can be applied in suspended wells, but it is impossible to make measurements during the drilling with their help since they do not have the required shock, vibro- and temperature resistance.
Oil-and-gas industry needs a single means to renew the drilling works and simultaneous determination of drilling parameters.
In this case MEDICON suggests the following two-stage strategy:
- completion of HRG development for repeated well penetration renewal;
- further development of the drilling parameter determination system together with the customer.
Oil-and-gas industry (together with such HRG suppliers as Litton and Honeywell) has financed several programs directed at the application of aerospace HRGs in drilling, but the programs have failed since the gyros didn’t meet the requirements on shock, vibro- and temperature resistance and didn’t have the needed size.
But despite earlier poor results, oil-and-gas industry keeps seeking technological solutions and suppliers of the HRGs which could meet its requirements.
According to our customers’ opinion, MEDICON HRGs do meet the requirements of the application in for repeated well penetration.
One of the main obstacles for HRG application in the sphere of making measurements during the process of drilling is the size, which is limited by the tube dimensions. Navigation system must be installed in the protective hosing of 40 mm in diameter and up to 1.2 km in length.
Among all the gyros only MEDICON gyroscopes meet the requirements of oil-and-gas industry regarding the size or even outdo them.