Method for updating a geologic model by seismic data
First Claim
1. A method allowing prediction of petrophysical characteristics of an underground reservoir, comprising:
- constructing a geologic model from geologic measurements acquired in depth;
simulating in depth seismic data, acquisition in time of seismic measurements on which at least two seismic markers distant from one another by an observed thickness in time Δ
Tobsm,n are identified;
making the geologic model consistent with the seismic measurements by minimizing an objective function;
simulating in depth seismic velocities allowing estimation of the thickness in depth Δ
Zestm,n of the markers, and simulating an error ε
simm,n made on this estimation;
carrying out time conversion of the seismic data simulated in depth by means of an interval velocity deduced from the observed thickness in time Δ
Tobsm,n and from the error ε
simm,n;
updating the interval velocity by comparing, within the objective function, the observed thickness in time Δ
Tobsm,n with a thickness in time Δ
Tsimm,n simulated from the seismic data, and by modifying said simulation of said error ε
simm,n;
carrying out the consistency enforcement operation by minimization of the objective function by comparing the seismic measurements with the simulated seismic data converted to time; and
predicting the petrophysical characteristics of the underground reservoir from the geologic model.
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Abstract
A method of predicting petrophysical characteristics of an underground reservoir by constructing a geologic model consistent with seismic measurements is disclosed which permits optimization of oil reservoir development schemes. A geologic model, from which seismic data are simulated in depth, is constructed in depth. The geologic model is made consistent with seismic measurements acquired in time by minimization of an objective function by comparing the seismic measurements with seismic data simulated from the geologic model and converted to time. During minimization, the interval velocities used for conversion are updated by comparing, within the objective function, an observed thickness in time ΔTobsm,n between two markers with a thickness in time ΔTsimm,n simulated from the seismic data, and by modifying simulation parameters such as the error εsimm,n on the thickness of the two markers estimated in depth.
48 Citations
16 Claims
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1. A method allowing prediction of petrophysical characteristics of an underground reservoir, comprising:
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constructing a geologic model from geologic measurements acquired in depth; simulating in depth seismic data, acquisition in time of seismic measurements on which at least two seismic markers distant from one another by an observed thickness in time Δ
Tobsm,n are identified;making the geologic model consistent with the seismic measurements by minimizing an objective function; simulating in depth seismic velocities allowing estimation of the thickness in depth Δ
Zestm,n of the markers, and simulating an error ε
simm,n made on this estimation;carrying out time conversion of the seismic data simulated in depth by means of an interval velocity deduced from the observed thickness in time Δ
Tobsm,n and from the error ε
simm,n;updating the interval velocity by comparing, within the objective function, the observed thickness in time Δ
Tobsm,n with a thickness in time Δ
Tsimm,n simulated from the seismic data, and by modifying said simulation of said error ε
simm,n;carrying out the consistency enforcement operation by minimization of the objective function by comparing the seismic measurements with the simulated seismic data converted to time; and predicting the petrophysical characteristics of the underground reservoir from the geologic model. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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Specification