The Research Of Prediction Technology For Pore Pressure And Fracture Pressure In Talaha Area

During drilling, in order to design reasonable density of mud and suitable wellbore structure , accurate pore pressure data and fracture pressure data are needed.Predicting pressure is essential to protecting oil layer and gas layer andincreasing the success ratio of drilling and reducing drilling cost.In recent year, with the development of exploration and production and theincrease of the number of drilling in Talaha area, such kind of drilling accidentas blowout , leaking, etc sometimes occurred during drilling operation. For example,in the course of drilling these exploration well, Y35, Y351, Y37, Y62, Y64, Y66,Y67, Y87 and Y901 , some kinds of accidents have happened.In the past ,the pore pressure and the fracture pressure were decided byexperience. In some area ,because the operator did not know the correct pressuresituation and distribution, it unavoidably led serious economy loss. It is hightime to find a suitable method to predict and evaluate the pore pressure and fracturepressure ,so as to ensure the safety of drilling and the stability of well andaccelerate drilling and reduce the drilling accident and the damage to the oil andgas layer and lower drilling risk and cost.In the aspect of researching the pore pressure prediction technology of Talahaarea , we analyse the advantage and disadvantage of seism method, dc index method,well logging method and effective stress method. We select four wells to testifythese methods by calculating pore pressure with these kinds of methods and comparingtheir results with the real measurment results. At last ,we get the conclusion:the well logging methods is more reliable and suitable than the other three methods.In the aspect of researching the fracture pressure prediction method, we buildthe prediction model from the angle of the stone mechanics and on the basis of thedamage of the formation being related to the stress of well .We establish therelation between static and dynamic mechanical parameters by doing core experiments.And make the prediction model be suitable to Talaha area. The results of the 4selected wells measured up the real measurement results.At last, according to the real geology condition of Talaha area, we gain a goodand useful technology of pore pressure and fracture pressure which is suitable toTalaha area by synthesizing theory analysis , experiments and practice. At the sametime , the result is effective and helpful to real operation . It can be used bysome other familiar area.