Low-permeability clastic rock reservoir effectiveness evaluation method based on development permeability lower limit

Abstract

The invention discloses a low-permeability clastic rock reservoir effectiveness evaluation method based on a development permeability lower limit, and belongs to the technical field of exploration and development of petroleum and natural gas. The method comprises the following steps: A, calculating an effective development permeability lower limit under the constraints of economic limit primary oil and a development thickness; B, performing evaluation parameter optimization and single scoring based on a permeability difference value; C, computing a weight coefficient and a comprehensive score based on grey correlation analysis; D, performing low-permeability reservoir effectiveness classified evaluation based on an economic primary liquid amount. By adopting the method disclosed by the invention, the key problems of inaccurate computation of a physical property lower limit, difficulty in determining a rational evaluation parameter, uncertainty in a practical classification standard and the like in low-permeability reservoir effectiveness classified evaluation are solved, and the accuracy and practicability of effectiveness classified evaluation of a low-permeability clastic rock reservoir are improved.

Description

technical field [0001] The invention relates to oil and gas exploration and development technology, in particular to a method for evaluating the effectiveness of low-permeability clastic rock reservoirs based on the lower limit of development permeability. Background technique [0002] With the continuous improvement of oil and gas exploration and development, the target of clastic rock oil and gas exploration and development gradually shifts to low permeability, ultra-low permeability and ultra-low permeability reservoirs. Because low-permeability clastic rock reservoirs have the characteristics of fine pore throat, complex structure, poor pore-permeability correlation, nonlinear seepage, and strong heterogeneity, the physical properties of low-permeability reservoirs are worse than those of conventional oil and gas reservoirs. According to the classification standard of layers, low-permeability clastic rock reservoirs are all unfavorable reservoirs. In fact, there are also...

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Problems solved by technology

[0008] In view of this, the main purpose of the present invention is to provide a method for establishing actual geological conditions, effective development permeability lower limit, permeability difference (the difference between the reservoir permeability value at a certain depth and the corresponding depth effective development permeability lower limit) ), the economic initial fluid production (average daily fluid production minus the economic limit initial fluid production) is a classification and evaluation method for the effectiveness of low-permeability clastic rock reservoirs to solve the lower limit of physical properties in the effectiveness classification and evaluation of low-permeability reservoirs Improve the accuracy and practicability of the classification and evaluation of the effectiveness of low-permeability clastic rock reservoirs by addressing key issues such as inaccurate calculations, difficulty in determining reasonable evaluation parameters, and unclear practical classification standards

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