Integrated reconstruction method of temporary plugging diversion and fracture support in fractured carbonate reservoirs

Abstract

The invention provides an integrated reconstruction method of temporary blocking steering and crack supporting for crack-type carbonate rock reservoirs. When the rock stratum required reconstruction is the 1 layer, the method comprises following steps: step A1 pump-infusing prepad fluid and inner crack complex temporary plugging system to the stratum; step B1 pump-infusing acid having variable-viscosity to the stratum; step C1 pump-infusing sand-carrying fluid and displacing liquid to the stratum to complete reconstruction; When the rock stratum required reconstruction is the 2 layer, the method comprises following steps: step A2 pump-infusing prepad fluid and inner crack complex temporary plugging system to the stratum; step B2 pump-infusing acid having variable-viscosity to the stratum; step C2 pump-infusing gel fracturing fluid containing crack complex temporary plugging system the and displacing liquid to the stratum; according to the number of layers requiring reconstruction, the step A2 to step C2 are repeated, wherein, at the last pump-infusing, sand-carrying fluid is infused instead of gel fracturing fluid containing crack complex temporary plugging system to complete the reconstruction. The method can realize integration and synchronization of temporary blocking steering and crack supporting.

Description

technical field [0001] The invention relates to an integrated transformation method for temporary plugging diversion and fracture support of fractured carbonate rock reservoirs, and belongs to the technical field of production stimulation and transformation of oil and gas wells. Background technique [0002] For acid fracturing in high temperature, deep, fractured carbonate reservoirs, due to the fast reaction rate of acid rock, the effective action distance of acid liquid is short, and it is difficult for the fracture ends to provide effective conductivity, while the fracture entrance is difficult to provide due to the acid liquid and fractures. Long-term contact, the damage to the mechanical strength of rock by acid liquid makes the conductivity of acid-etched fractures in the area near the wellbore poor. 2013(s2): 3016-3021), affecting the effect of acid fracturing transformation. At the same time, for fractured carbonate reservoirs, it is necessary to increase the volum...

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Problems solved by technology

[0002] For acid fracturing in high temperature, deep, fractured carbonate reservoirs, due to the fast reaction rate of acid rock, the effective action distance of acid liquid is short, and it is difficult for the fracture ends to provide effective conductivity, while the fracture entrance is difficult to provide due to the acid liquid and fractures. Long-term contact, the damage to the mechanical strength of rock by acid liquid makes the conductivity of acid-etched fractures in the area near the wellbore poor. 2013(s2): 3016-3021), affecting the effect of acid fracturing transformation

At the same time, for fractured carbonate reservoirs, it is necessary to increase the volume of stimulation to achieve lateral and vertical diversion of fractures to further improve the stimulation effect. At present, the most effective temporary plugging in fractures is temporary plugging at the ends of fractures, such as sand screen at the ends, while other areas in fractures The temporary plugging of the fracture is difficult to achieve the plugging of the entire fracture height, and can only increase the net pressure in the fracture, while the temporary plugging of the fracture is difficult due to the large opening of the fracture, and the simple particle temporary plugging agent will Scattered (Yang Zhaozhong et al., a multi-stage temporary plugging deep network acid fracturing method, CN106194145), it is difficult to achieve the optimal plugging effect

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