Carbonate Formation Pressure Prediction In The TH Block

Formation pressure is a very important parameters in the oil and gas exploration and development, accurate formation pressure predictions is the base of drilling engineering design and construction of foundation, also is key to the sure drilling mud density, body structure of drilling well control and completion techniques etc. It has a great economic value and scientific significance in reducing drilling engineering accident, enhancing drilling efficiency, shortening the drilling cycle, reducing the drilling cost, eliminate drilling troubles, certain reservoir driving and connected to determine its . This paper comprehensive use geological and logging data to sum up the geophysical basic methods of formation pressure prediction, based on the research of scholars both at home and abroad, and buildup a set of pressure prediction technology which is suitable for carbonate area in the light of TH carbonate formation block.This paper firstly use Greenberg - castana formula to calculate initial S-wave, then calculate the skeleton's elastic modulus, with the help of Gassmann equation inversion, reachieve the known mineral rock properties, fluid property and porosity, through the Gassmann equation to forward modeling the original fluid state of rock's p-wave and s-wave, after multifold iteration, we will get a reasonable s-wave velocities and related dynamic and static the elasticity modulus. Then this paper use effective stress method which is based on Anderson model to calculate pore pressure and fracture pressure section, and established a single-well monitor pressure mode which is match the measured data and geology rule. In the test model under the restriction of the false, introduced pseudo poison's ratio, make full use of prestack random inversion and prestack elastic impedance inversion results with the multiple regression method, and establish experience formula which is suitable for carbonate formation pressure prediction, predicte the full 3d TH block's pore pressure and fracture pressure. The results of the study show the prediction pressure is in good agreement with the test data, the match accuracy is high, the way of think is distinct, the operation is simple, so this method can be applied other similar carbonate block.