Horizontal well pre-fracturing injection fluid development method based on three-dimensional fracturing well pattern

Abstract

The invention provides a horizontal well pre-fracturing injection fluid development method based on a three-dimensional fracturing well pattern. The method comprises the steps that 1, a target horizontal well is deployed in an oil layer, and the target horizontal well is not fractured, a first horizontal well parallel to the target horizontal well is deployed at the upper part of the horizontal section of the target horizontal well, and fracturing is carried out on the first horizontal well to form a crack perpendicular to the direction of the horizontal section of the target horizontal well,a vertical well is deployed around the target horizontal well, and fracturing is carried out on the vertical well to form another crack of which the trend is parallel to the direction of the horizontal section of the target horizontal well and the position is lower than that of the horizontal section of the target horizontal well; 2, under the condition that the target horizontal well is not fractured and does not produce, the first horizontal well and the vertical well serve as injection wells, and energy supplementing fluid is injected into a stratum; and 3, after stratum energy supplementing fluid injection is completed, fracturing is carried out on the target horizontal well, and well opening production is carried out, and meanwhile, the first horizontal well and the vertical well which sever as the injection wells are converted into oil production well for well opening production.

Description

technical field [0001] The invention belongs to the technical field of oil field development, in particular to a development method for injecting fluid before horizontal well pressure based on a three-dimensional fracturing well pattern. Background technique [0002] Unconventional oil reservoirs are the main object of current exploration and development work and an important part of my country's future oil and gas resources. Due to the low pressure coefficient and low permeability of unconventional reservoirs, fracturing is usually used for initial development, so as to obtain high initial productivity. However, as the reservoir energy decreases, the production decline rate of fractured horizontal wells is faster. Therefore, how to effectively increase the energy of unconventional reservoirs to suppress production decline and increase the stable production period has become a key issue in the field of oilfield development. [0003] Considering that after horizontal well fr...

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Problems solved by technology

However, the existing advanced fluid injection method (CN111456693A, the method of advanced gas injection and continuous gas injection in tight-shale reservoirs to replenish formation energy) is mainly aimed at simultaneous injection and production of a single horizontal well, which cannot give full play to the advantages of the well pattern. The regular reservoir has low permeability and limited gas flow capacity, and the injected gas is only concentrated in a small area around the horizontal well, and the inter-well sweep area is small, which limits the effect of inter-well energy replenishment and reserve production; and the The method mainly uses mixed gas for advanced injection, and 10%-30% of the injected gas is CO2. Due to the high cost of CO2 and the difficulty of transportation, it is limited Application of the method

In addition, the existing production method of different well injection into this well (for example, CN107575195A, a method for miscible flooding of natural gas hydrate in parallel horizontal wells) on the one hand develops the object (natural gas hydrate) and crude oil in phase state, physical property, flow There are significant differences in the law and other aspects. On the other hand, as disclosed in CN107575195A, step 5 (arranging the injection system, the injection system includes the ground supply system and the downhole injection system) is all energy-enhancing fluid injection after the fracturing of the target horizontal well. The realization of energy supplement before fracturing cannot effectively change the stress conditions before fracturing, which is not conducive to the formation of complex fracture networks; it will also lead to too fast initial deceleration after the production of horizontal wells, which cannot effectively prolong the stable production period of horizontal wells. The degree of recovery improvement is relatively limited

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