Method for predicting transversal wave velocity of carbonatite rock reservoir

Abstract

The invention provides a method for predicting the transversal wave velocity of a carbonatite rock reservoir and relates to the technical field of geophysical exploration. The method comprises the following steps: determining the mineral component, the reservoir porosity as well as the fluid saturation of the reservoir; dividing the reservoir porosity into a rigid porosity, a fracture porosity and a clay porosity; obtaining the parameters of each mineral in the reservoir; calculating the bulk modulus Km and the shear modulus mum of a rock matrix through a Voigt-Reuss-Hill average model; calculating rhom; generating kfl and rhofl; generating the equivalent density rhodry of a rock dry skeleton; sequentially adding the porosities into the rock matrix through a DEM model, and calculating Kdry and mudry; carrying out fluid replacement on the rock dry skeleton through a low-frequency Gassmann equation so as to generate the density rho of a saturated fluid rock; calculating Ksat and musat; calculating the longitudinal wave speed (as shown in the description) and the transversal wave speed (as shown in the description) of the saturated fluid rock, inverting a virtual fracture porosity phi'f by a simulated annealing method according to a first relative error (as shown in the description) or a second relative error of rho and rhoo; replacing phif with phi'f, returning and calculating to generate the transversal wave speed V1 of the carbonatite rock reservoir.

Description

technical field [0001] The invention relates to the technical field of geophysical exploration, in particular to a method for predicting shear wave velocity of carbonate rock reservoirs. Background technique [0002] At present, carbonate reservoirs are one of the most important targets of oil and gas exploration in the world. The oil and gas reserves discovered from carbonate rock reservoirs are close to half of the world's oil and gas reserves, and the production has reached more than 60% of the total production. Carbonate rocks mainly include three types of storage spaces: pores, caves and fractures. Pores and caves are the main storage spaces, and fractures are the main percolation channels and storage spaces. This is the biggest difference between carbonate rocks and clastic rocks. The pore structure is complex and diverse, so Carbonate reservoirs have strong heterogeneity, which makes it very difficult to obtain their elastic modulus. [0003] S-wave velocity is one ...

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Problems solved by technology

[0004] The embodiment of the present invention provides a method for predicting the shear wave velocity of carbonate rock reservoirs to solve the problem of lack of accurate prediction of the shear wave velocity of carbonate rock reservoirs in the prior art

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