A Geological Modeling Method for Internal Seepage Barriers in Offshore Oilfield Reservoirs

Abstract

The invention relates to a geological modeling method for internal seepage barriers in offshore oilfield reservoirs, comprising the following steps: collecting sensitive seismic attributes of the reservoirs to be measured to predict the distribution of internal seepage barriers in the reservoirs, and dividing the seepage barriers into non-permeable, There are three types of semi-permeability and permeability; according to the data of horizontal wells drilled through the seepage barrier in the reservoir to be measured, the basic data used to characterize the three types of seepage barriers are calculated respectively; the three types of non-permeability, semi-permeability and permeability are established respectively. The lithofacies model of similar seepage barriers; according to the attribute characteristics of seepage barriers, a virtual well is set in the lithofacies model, and the attribute characteristics of the three types of seepage barriers are simulated respectively to obtain the geological model of seepage barriers inside the reservoir. The invention effectively depicts the real distribution of the seepage barrier inside the reservoir, and makes up for the deficiency of the traditional utilization theory. By duplicating the actual drilled horizontal wells to set up virtual wells, the basic data of geological modeling are enriched, and the characterization accuracy of seepage barriers in geological models is improved.

Description

technical field [0001] The invention relates to a geological modeling method for internal seepage barriers of offshore oilfield reservoirs, belonging to the field of oil and gas field development. Background technique [0002] The reservoirs of domestic offshore oilfields are mainly fluvial facies and delta facies. During the depositional period, due to the erosion of the channel and the lateral migration and swing, the sand bodies of different periods are superimposed in space, resulting in rapid lateral changes of the reservoir. , Strong heterogeneity, seepage barriers of various origins are widely developed inside the reservoir, hindering the flow of underground oil, gas and water. In the stage of oilfield development, problems such as ineffective injection and production, partial enrichment of remaining oil, and low recovery degree of reservoirs caused by seepage barriers blocking fluid have gradually emerged. Therefore, the prediction and characterization of seepage bar...

AI Technical Summary

Problems solved by technology

However, the existing methods have many points to be improved: first, some methods rely on the dense well pattern data of onshore oilfields, which are difficult to apply to the current situation of large well spacing and relatively scarce well data in offshore; It is difficult to truly characterize the distribution of seepage barriers inside the reservoir and the barrier effect on fluids when the theoretical geological model is established.

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