Method and Apparatus for Performance Prediction of Multi-Layered Oil Reservoirs

Abstract

The present invention discloses a method and an apparatus for predicting performance profiles of multi-layered oil reservoirs, wherein the method comprises: dividing the multi-layered oil reservoirs into a plurality of blocks, and determining a reservoir type, formation factor Kh and an evaluated reserves of each layer in each block; selecting a block representing geologic features of the multi-layered oil reservoirs from the plurality of blocks as a representative block, to build a fine geological model of the representative block; building corresponding fine numerical simulation model according to the fine geological model of the representative block, and determining type curves of different reservoir types under different development strategies; determining a relation curve between Kh and well injection rate for injectors and a relation curve between Kh and well production rate for producers in the multi-layered oil reservoirs under different restrictive conditions; predicting performance of the multi-layered oil reservoirs according to the type curve, the relation curve between Kh and well injection rate, the relation curve between Kh and well production rate, and the reservoir type, formation factor Kh and evaluated reserves of each layer in each block.

Description

RELATED APPLICATION[0001]This application claims priority under 35 U.S.C. §119 or 365 to China, Application No. 201510349577.8, filed Jun. 23, 2105.[0002]The entire teachings of the above application(s) are incorporated herein by reference.FIELD OF THE INVENTION[0003]The present invention relates to the field of performance prediction techniques for oil and gas reservoir development, and particularly, to a method and an apparatus for performance profile prediction of the multi-layered oil reservoirs.BACKGROUND OF THE INVENTION[0004]Lots of human and material resources will be spent in building a fine geological model for the large oil and gas field, while it is still difficult to ensure that the sand body distribution, reservoir connectivity across the whole oil field for the fine geological model are consistent with the expectations. Meanwhile, the fine geological model of the whole oil reservoirs is also usually up-scaled due to the reasons such as a large number of grids, much sl...

AI Technical Summary

Benefits of technology

[0006]The embodiments of the present invention provide a method for predicting the whole performance profiles of the multi-layered reservoirs, which not only ensures the prediction accuracy of the multi-layered oil reservoirs, but also reduces the man-power and improves the working efficiency. The method comprises:

[0012]The embodiments of the present invention provide an apparatus for predicting performance profile of multi-layered oil reservoirs, which not only ensures the accuracy of the prediction of the total output of the multi-layered oil reservoirs, but also reduces the man-power and improves the working efficiency. The apparatus comprises a processor configured to:

[0018]As compared with the current universal method which predicts the performance profile of the whole oil reservoirs just according to the typical production curves of different types (high, middle, low, etc.) of production wells, the technical solution provided by the embodiment of the present invention divides the whole oil reservoirs into a lot of blocks according to the stacked style of reservoir types for the whole oil reservoirs, selects a representative block representing geologic features of the whole reservoirs from the plurality of blocks to build a fine geological model, carries out numerical simulation based on the fine geological model of the block to study the optimum development strategies for the multi-layered oil reservoirs, and generates relations between water cut and oil recovery efficiency of different reservoir types under different development strategies which is used to predict the performance profile of the whole oil field combined with the classification result of the reservoir types of the whole oil reservoirs, and results of the relationship between well production rate and Kh, and the relation between well injection rate and Kh. The prediction result based on the proposed method is more accurate and reliable, and performance profiles of development plans for the whole oil reservoirs can be quickly generated, thus the man-power are greatly saved and the working efficiency is improved.

Problems solved by technology

Lots of human and material resources will be spent in building a fine geological model for the large oil and gas field, while it is still difficult to ensure that the sand body distribution, reservoir connectivity across the whole oil field for the fine geological model are consistent with the expectations.

Meanwhile, the fine geological model of the whole oil reservoirs is also usually up-scaled due to the reasons such as a large number of grids, much slow calculation and time consuming of numerical simulation, etc., and then the numerical simulation is performed based on the up-scaled model.

However, the up-scaled model cannot accurately represent some strong heterogeneity inside the reservoirs.

Currently, the unconventional oil and gas reservoirs at home and abroad have problems on the large whole field reservoir numerical simulation, thus the numerical simulation research on the whole oil and gas reservoirs cannot be carried out.

But the development of the conventional multi-layered oil reservoirs is complex, and the total performance of the oil reservoirs cannot be simply predicted based on performance curves of the existed production wells.

Thus the influences of different development modes and stimulations on the development performance cannot be characterized by typical performance curves through classifying the producers into several typical types, which is restrictive and one-sided at certain extent, and the accuracy of the prediction of the performance of multi-layered reservoirs is low.

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