Geological modeling method for internal seepage barriers in offshore oilfield reservoir

Abstract

The invention relates to a geological modeling method for internal seepage barriers in an offshore oilfield reservoir. The method comprises the following steps: collecting sensitive seismic attributesof a to-be-measured reservoir, predicting distribution of internal seepage barriers in the reservoir, and classifying the seepage barriers into three classes of impermeability, semi-permeability andpermeability; according to horizontal well data of seepage barrier drilling in the to-be-measured reservoir, carrying out statistics of basic data for representing three types of seepage barriers; establishing lithofacies models of impermeable, semi-permeable and permeable seepage barriers seepage barriers respectively; and according to the attribute characteristics of the seepage barriers, setting virtual wells in the lithofacies models and simulating attribute characteristics of the three types of seepage barriers to obtain a geological model of the seepage barriers in the reservoir. According to the invention, real distribution of the seepage barriers in the reservoir is effectively described and defects of the traditional utilization theory are overcome. Since the virtual wells are setby y copying the actually-drilled horizontal well, the basic data of geological modeling are enriched and the characterization precision of the seepage barriers in the geological model 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.

Images