Pressure-limited and discharge-quantity-unlimited fracturing method for increasing shale gas crack transforming size

Abstract

The invention discloses a pressure-limited and discharge-quantity-unlimited fracturing method for increasing the shale gas crack transforming size. The pressure-limited and discharge-quantity-unlimited fracturing method comprises the steps that (1) reservoir evaluation before fracturing and real-time evaluation of the fracturing construction earlier stage are conducted; (2) a layered small testing fracturing test is conducted on a straight well guiding well; (3) simulation analysis is conducted through software MEYER; (4) normal fracturing construction is conducted, and in the construction midway, one-time or two-time instantaneous pump stopping is conducted; (5) the wellhead construction anticipated pressure is derived reversely through the well bottom pressure; (6) as long as the wellhead construction pressure is lower than the anticipated pressure of the step (5), the discharge quantity is increased to enable the wellhead pressure to approximate the anticipated value; and (7) if the wellhead construction pressure after the discharge quantity is increased still does not reach the anticipated pressure, the construction sand-liquid ratio is increased. According to the pressure-limited and discharge-quantity-unlimited fracturing method for increasing the shale gas crack transforming size, the various problems caused by using a discharge-quantity-limited method can be solved, so that the actual after-fracturing transforming size of a shale reservoir is increased, and the complexity of man-made cracks is improved.

Description

technical field [0001] The invention relates to the field of petroleum exploitation, and more specifically, relates to a fracturing method for increasing the volume of shale gas fracture reconstruction with limited pressure and unlimited displacement. Background technique [0002] In shale gas fracturing construction, on the premise of ensuring construction safety, how to maximize the fracture complexity and reconstructed volume is an eternal theme. However, in the current fracturing operation, the displacement is mainly maintained at a basically constant rate, which has a certain impact on our goal of increasing the complexity of the fracture and the volume of the reconstruction. [0003] At present, from a technical point of view, the method of limiting the displacement we use in fracturing construction has the following main problems: [0004] 1) The net pressure increase range of the main fracture is limited. Especially for shale with good brittleness, during the proce...

AI Technical Summary

Problems solved by technology

It can improve the current fracturing process, such as: limited net fracturing promotion range of fractures, difficulty in extending fractures at high peaks, early settlement of proppant and the widening of far-well fractures due to early settlement of proppant. Various problems such as sand plugging in the later stage of construction caused by narrowing will increase the actual post-fracture volume of shale reservoirs and the complexity of artificial fractures