Abstract:
Способ получения априорного годографа для выполнения литолого-стратиграфической привязки относится геофизике для получения сейсмических разрезов изображений геологической среды. Для снижения трудоемкости и повышения достоверности соответствия горизонтов временного разреза и ГО скважины он включает действия, дающих данные методов общей глубинной точки, СК, ВСП, АК, ГГК-П, ГО и проверяющие их качество, дающие эталонные значения интервальных скоростей, получают исходный годограф и рассчитывают синтетическую сейсмограмму, проводят контроль качества, и вводят постоянную временную поправку для посадки на верхний ОГ литолого-стратиграфического комплекса и вновь рассчитывают синтетическую сейсмограмму и проводят контроль качества, вводят «нулевую точку» в полученный годограф, дополнительно, на одну и более точек ниже забоя, проводят расчет синтетической сейсмограммы и контроль качества, вновь рассчитывают и вводят поправку для посадки на нижний ОГ литолого-стратиграфического комплекса по формуле dTi=Hi*dT н/ H н , где dTi - поправка, вводимая в каждую i-тую точку последнего годографа, следующую за точкой верхнего ОГ; dT н =tн ОГТ -tн ск - поправка, вносимая в последний годограф для посадки на нижний ОГ, tногт - значение времени снятое с временного разреза МОГТ (в точке скважины) для экстремума отраженной волны соответствующей нижнему ОГ; tн ск - значение времени, снятое с последнего годографа СК, ВСП для геологической отметки нижнего ОГ; Hi - значение геологической отметки i-ой точки последнего годографа СК, ВСП; Н н - значение геологической отметки нижнего ОГ по диаграммам ГИС; после этого вновь рассчитывают синтетическую сейсмограмму с последующим контролем качества, и следом переносят точки полученного годографа на ближайшие акустически слабые границы и повторно рассчитывают синтетическую сейсмограмму, получая априорный годограф.
Abstract:
The present invention relates to a method for synchronizing continuous seismic survey. In particular, the present invention employs a semaphore scheme for the vibes to autonomously and continuously initiate sweeps, thereby decoupling the vibratory source subsystem from the recording subsystem. By using a continuous recorder and the method of the present invention, the recording trucks and the observers can be eliminated, and the vibratory sources can be initiated more efficiently than conventional systems.
Abstract:
A seismic data acquisition system is configured to collect seismic data. The system includes a marine source array configured to be attached to a fixed structure floating at the water surface and including vibratory source elements; and a controller configured to control the vibratory source elements so that a beam formed by the source array is steerable.
Abstract:
Apparatus, computer instructions and method for controlling an energy output of a source array (300) to be used in a seismic survey for illuminating a subsurface. The method includes generating (600) a model ( β ) based on up-going (U) and down- going (D) components of seismic waves generated by source elements (300-i) that form the source array (300); calculating (602) the amplitudes and phases of each source element (300-i) based on the model ( β ); and driving (604) the source array (300) based on the calculated amplitudes and phases for the source elements (300- i) so that a ghost generated by the source array (300) is reduced at emission.
Abstract:
A method for determining the mineralogical, or geological, or chemical configuration of a structure, comprising: illuminating the structure with a broadband laser source that emits electromagnetic radiation having a plurality of wavelengths, recording an image of the surface of the structure that includes information on the spectrum of the radiation reflected or diffused by the structure.
Abstract:
Method, source array and seismic vibro-acoustic source element for seismic data acquisition. The method includes storing (1000) in a controller (322) a library of beam form factor sets associated with a source array (300) and corresponding regions (210, 220, 230) to be surveyed; towing the source array (300) along survey lines (204-i) over the regions (210, 220, 230) to be surveyed; selecting a beam form factor set from the library to be applied to the source array (300) for each region; and actuating the source array (300) based on the selected set of beam form factors and a position of the source array (300) relative to the regions (210, 220, 230). Each set of beam form factors maps to a corresponding region of an area (202) to be surveyed.
Abstract:
Systems and methods for calibrating resistivity tools in environments with radio- frequency (RF) noise are described herein. The method may include receiving a first measurement from a resistivity tool. The measurement may be taken with the resistivity tool elevated to reduce ground effects on the measurements. The first measurement may be altered by excluding at least some RF noise from the first measurement. The RF noise may be a by¬ product of the resistivity tool being elevated. Additionally, the resistivity tool may be calibrated using the altered first measurement.
Abstract:
A system comprises towed marine geophysical equipment, adapted for towing through a body of water; and a surface covering, comprising a textural attribute of shark skin, attached to the marine geophysical equipment. A method comprises towing marine geophysical equipment having a surface covering, comprising a textural attribute of shark skin, attached thereto.
Abstract:
In seismic survey for icy waters, streamers are towed behind a vessel under the water's surface to avoid ice. GPS readings may not be consistently obtained because the ice prevents a tail buoy with a GPS receiver from trailing from streamer at the surface. Instead, a device tows on the streamer under the water's surface. The streamer's absolute position is tracked by intermittently bringing the towed device toward the surface so GPS readings can be obtained. The streamer's absolute position can then be used in conjunction with compass readings and can correlate various seismic sensor signals obtained along the streamer during the survey. The compass readings can be corrected for declination using declinometer readings, which can be compensated for iron effects from the vessel or other device carrying the declinometer.