METHOD FOR PREDICTION OF PARAMETERS OF GAS DEPOSITS Russian patent published in 2016 - IPC G01V1/30 

FIELD: seismology.

SUBSTANCE: invention relates to methods of complex interpretation of seismic data and can be used for forecasting of gas deposits. Using data of seismic survey VVR CMP 2D and 3D, effective gas-saturated thickness and lithologic non-uniformity in gas deposits of aptian-albian-cenomanian terrigenous complex at kinematic attributes is predicted. Two or more reflecting horizons are traced, one of which is located above gas deposit, and other or other below it. Method includes calculating map of time thickness ΔT and link of kinematic anomalies of interval time of time thickness ΔT with gas-saturated thickness Hefg in wells is determined. At low quality of horizon associated with gas deposit, normalisation is carried out for series of maps of time thickness ΔT and their addition in order to amplify useful anomalies associated with Hefg, and levelling non-information random anomalies. As a result, map complex kinematic parameter is obtained, re-computed based on a regression equation into a predictive map of gas-saturated thickness Hefg. From map of complex kinematic parameter, component of height of deposit and local anomalies of second order, associated with lithographic heterogeneity is selected. Link between map of local components with parameter of lithology is determined. By changing parameters of filtration trend of time thickness ΔT, a high convergence of local components with parameter of lithology is achieved, to predict its distribution along area of seismic survey. Prediction result is assessed with a priori degree of lithographic heterogeneity. Prediction is then propagated to model of calculating reserves and areas of increased grittiness and expected high productivity of gas deposit are selected for scheduling drilling of producer wells.

EFFECT: technical result is improved reliability of predicting main parameters of gas deposit, shorter time for assessment of reserves and preparation of gas deposits for operation by reducing number of exploration wells, reduction of technogenic load on environment.

1 cl, 2 dwg