Calcium-bearing Sandstone Reservoir Identification Based on an Improved S-wave Velocity

Nowadays, many kinds of shear-wave forecasting methods have been provided by researchers, but most of those methods still remain in the stage of good agreement between forecasted curve and measured curve. It is a burning issue and it is difficult to extend it to those wells which lack of shear-wave data, and it has seldom been used in actual pre-stack seismic inversion with a good result. It is critical that the shear-wave velocity estimation to identify the sandstone reservoir using pre-stack simultaneous inversion in old fields which calcium developed and absent shear-wave velocity. In this case, the calcium-bearing shaly sand formation model was established to estimate shear-wave velocity. It was found from the early research that the porosity and mineral content was the key to shear-wave estimation. And the result’s accuracy of logging data interpretation was improved through the well logging formation components analysis method to a great degree. The shear-wave estimated method of Xu & White model and an improved method for calcium-bearing shaly sand formation was applied into reservoir prediction separately. It shows that the sandstone reservoir could be identified clearly from shaly sand formation which contains calcium from the results inverted through the improved shear-wave.