Distinguished Instructor Short Course 2000

Robert Garotta

CCG Group

Shear Waves from Acquisition to Interpretation


Robert GarottaMulticomponent studies are perhaps today at the same stage that 3-D studies were fifteen years ago. The renewed interest in shear waves is obvious, especially in the subsea environment where millions of dollars are being spent on acquiring the elastic response of the earth. Because shear wave-related techniques are raising the interest of the E&P industry, this course addresses, through case histories, the practical aspects of multicomponent data acquisition, processing and interpretation.

Although the industry resorts to shear wave propagation when the usual compressional response is poor, the main promise of the shear wave response is in its combination with the compressional one. However, this is possible only when the quality and resolution of the two responses are similar.

The first part of the course is devoted to overcoming the difficulties associated with shear wave acquisition. Converted mode operation is covered in detail using real-life examples. The particularities of sea bottom receivers are also examined.

The second part of the course reviews the processing and the main challenges of the shear converted modes: static corrections, gathering, velocity analysis and compensation for shear wave splitting in axial anisotropy. The course gives a detailed description of processing sequences. 2-D and 3-D results, yielding natural axis orientation of layers, are compared in shear and PS converted modes.

The third part of the course is devoted to case histories where new attributes, such as Vp/Vs ratio, crack density, or fracture orientation, are illustrated in a reservoir characterization context. These case histories can guide the geophysicist to decide if a particular geological situation can be best handled using shear waves.

Who Should Attend?

For those who are interested in the potential of the methodology involving shear waves, it is a good opportunity to learn from one of the leaders in this field and to maximize the chances of getting the most out of the data when big investments are at stake.