METHOD TO DEFINE MAGNETIC AZIMUTH IN WELL INCLINOMETER IN PROCESS OF DRILLING

FIELD: measurement equipment.SUBSTANCE: method is based on using readings of projections H, H, hof classic triad of flux gates and two additional field sensors, spaced along the longitudinal axis Z of the inclinometer. As additional flux gates, they use uniaxial field sensors with axes of sensitivity directed along the axis Z, generating accordingly current values pf projections of the summary field h=H+Hand h=H+H, where H- projection of Earth field at inclinometer axis Z, and H, H- field intensity noise registered by additional sensors 1 and 2, and then they carry out calculation of the values H(1), H(2), H(3), representing three independent realisations of one and the same value of the projection H, cleaned from magnetic noise impact, in accordance with expressions: H(1)=h-(h-h)/1-K, H(2)=h-(h-h)/1-K, H(3)=h-(h-h)/1-K, where (h-h) characterises difference of readings of primary meters, responsible for local field gradient between sensors i and j, and values are scale coefficients, being permanent values for the entire time of well tunnelling, and which are experimentally determined at the initial stage of drilling works performance, for which purpose a string in assembled form is installed into vertical position with a zenith angle value in the range of (0÷15)° and lowered at such depth, when increment of difference in readings δ(h-h) in process of downward string movement does not exceed one-two count units.EFFECT: expansion of functional possibilities of an inclinometer due to higher accuracy of azimuth generation and provision of inclinometer operability under conditions of arbitrary nature of field distribution in a reading zone.2 cl, 1 tbl Изобретение относится к области инклинометрии и может быть использовано в нефте- и газопромысловой геофизике. Достигаемый технический результат - расширение функциональных возможностей инклинометра за счет более высокой точности выработки азимута и обеспечения работоспособности инклинометра в условиях произвольного характера распределения поля в зоне считывания. Способ основан на использовании показаний проекций H, H, hклассической триады феррозондов и двух дополнительных датчиков поля, пространственно разнесенных вдоль продольной оси Z инклинометра. В качестве дополнительных феррозондов используют одноосные с направленными вдоль оси Z осями чувствительности датчики поля, вырабатывающие соответственно текущие значения проекций суммарного поля h=H+Hи h=H+H, где H- проекция поля Земли на ось Z инклинометра, a H, H-