Full-range sand-adding yield increase construction method for oil well

Abstract

The invention discloses a full-range sand-adding yield increase construction method for an oil well, which comprises the following steps of: (1) selecting a reservoir with a volcanic cave type or a loose sandstone pore type or a fractured type, starting an injector pump, injecting an injected fluid at an initial displacement speed of between 1.5 and 2 m<3> / min, gradually increasing the displacement to be between 3 and 4.5 m<3> / min, and ensuring that the pressure of a bushing is gradually improved by between 2 and 3 MPa; (2) beginning to add sand and improving the sand ratio when the amount of the injected fluid reaches one or two pipe column volumes and the injected fluid enters the stratum, controlling the range of the sand ratio to be between 5 and 10 percent and the sand amount to be between 2 and 3.5 m<3>, and ensuring that the pressure of the bushing is improved by between 4 and 6 MPa; and (3) stabilizing the pumping displacement, adding the sand according to the range of the sand ratio of between 15 and 80 percent and the gradual increase of 5 percent for each adding in the whole process, ensuring the sand amount reaches between 2.5 and 4 m<3> at a sand ratio section of between 20 and 25 percent, and making the pressure of the bushing gradually improved by between 6 and 15 MPa. The method has the advantages that: the method improves the ability that oil gas flows into the well; the success ratio of the construction reaches over 95 percent, the liquid efficiency is improved by over 45 percent, the average yield increase of an individual well is between 350 and 550 tons, the construction cost is saved by between 150 and 200 thousand yuan, and the benefit is increased by between 300 and 500 thousand yuan; and the method solves the technical problems shown in non-continuous medium reservoirs such as high filtration loss and the like.

Description

technical field [0001] The invention belongs to oilfield production increase technology, in particular to a construction method for increasing production by adding sand in the whole process of oil wells. Background technique [0002] At present, hydraulic fracturing stimulation method is commonly used in oil fields to realize the stimulation of oil wells. The hydraulic fracturing stimulation method is developed based on the cemented strength of sandstone reservoirs. The hydraulic fracturing mechanism is based on the fracture mechanics of continuous homogeneous media in material mechanics. The process is to use 30-60% of the total injected liquid as The fracture-making liquid first forms hydraulic splitting fractures in the rock formation, and then mixes sand into the injected liquid and brings them into the opened fractures. When the injected liquid leaks into the rock formation, the sand brought in supports the hydraulically opened fractures. Fractures act as pathways for ...

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Problems solved by technology

Therefore, construction according to the conventional sandstone construction mode is not suitable for this type of reservoir. The mechanism of fluid loss and other aspects is complex, and technical problems such as high stress, high fluid loss, high fracture internal distortion, and difficult-to-control fractures will occur during construction; ② High sand plugging rate (25.4%) and high proportion of pre-fluid (55.2%) , low sand-to-liquid ratio (25%), short validity period (35-76d), difficult drainage, large investment, poor economy, etc.

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