Multi-section fracturing occurrence profile tracing monitoring and explaining method

Abstract

The invention provides a multi-section fracturing occurrence profile tracing monitoring and explaining method. The multi-section fracturing occurrence profile tracing monitoring and explaining method is suitable for a horizontal well multi-section fracturing technology and comprises the following steps that 1, in the horizontal well multi-section fracturing operation process, different kinds of water-based or oil-based tracer agents are injected into each layer section; and 2, in the fracturing fluid flow-back process, concentration changes of the different tracer agents in fracturing flow-back fluid are monitored regularly, the accumulative output rate of the tracer agents and the flow-back fluid volume are calculated according to the monitored concentration changes of the tracer agents, the flow-back fluid condition of a target layer is qualitatively and quantitatively analyzed, and therefore the effect after fracturing of each layer section is obtained. Through a fracturing tracing test, the visual understanding of the productivity contribution of each section of a stratum can be obtained, oil reservoirs and development engineers are helped to evaluate the fracturing effect, and the fracturing scheme is optimized; therefore, the fracturing scheme is scientifically and effectively perfected and optimized, the exploration and development cost is reduced, and the operation efficiency is improved.

Description

technical field [0001] The invention relates to the technical field of petroleum exploration, in particular to a method for trace monitoring and interpretation of multistage fracturing occurrence profiles. Background technique [0002] Productivity prediction of new wells is a key link in the preparation of development plans. Existing technologies are still based on the analogy method for the analysis of productivity changes and influencing factors of multi-stage fractured horizontal wells in tight oil reservoirs, especially the initial productivity prediction methods. Most of the formulas and models for the initial productivity of horizontal wells are based on Darcy's law and the factors of threshold pressure gradient or reservoir stress sensitivity are added. Currently, Lang Zhaoxin’s formula, Li Hujun’s formula and Fan Zifei’s formula are commonly used in the field. However, the relative error of predicting production capacity is still difficult or even unapplicable due t...

AI Technical Summary

Problems solved by technology

Currently, Lang Zhaoxin’s formula, Li Hujun’s formula and Fan Zifei’s formula are commonly used in the field. However, the relative error of predicting production capacity is still difficult or even unapplicable due to the fact that the pore throat size and seepage mechanism do not conform to Darcy’s law.

The applicable conditions of the analogy method are: similar formation pressure coefficient, similar reservoir lithology and physical properties, similar reservoir fluid properties, similar reservoir type and driving energy, etc., and the applicable conditions are very harsh. Production capacity is still not fully understood

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