Automatic control system and method for wellhead pressure return

Abstract

The invention belongs to the technical field of pressure control drilling engineering, and specifically relates to an automatic control system and method for wellhead pressure return. The system includes a first pressure sensor, a second pressure sensor, a third pressure sensor, a compensation pump, a throttle valve, a well depth sensor and an analysis controller. The problems that existing fine pressure control equipment has multiple matching equipment, complex pressure control systems and high input costs, is not in accordance with a low-cost development strategy of a Changqing oilfield andhas difficulties in later popularization are solved. The system achieves automatic control of the wellhead pressure return, meets the requirement of wellhead pressure control drilling in the whole process, improves the safety operation ability, reduces the risk of wellhead control in water injection area of the Changqing oilfield, and helps to develop a low-cost pressure automatic control system and an optimization matching process adapted to the wellhead pressure control drilling in the water injection area.

Description

technical field [0001] The invention belongs to the technical field of pressure-controlled drilling engineering, and in particular relates to an automatic wellhead back pressure control system and method. Background technique [0002] Wellhead managed pressure drilling is economical, effective, and reliable. Due to its less supporting equipment, lower investment cost, strong technical pertinence, it can effectively reduce well control risks, simple process, and strong operability. The area was quickly promoted, and safe drilling under different overflow conditions such as overflow water, associated gas, and leakage and overflow in the water injection area of ​​Changqing Oilfield was realized. However, the wellhead MPD operation implemented in the water injection area of ​​Changqing Oilfield is only limited to the normal drilling conditions to realize the control of the wellhead back pressure, which cannot meet the wellhead back pressure in the working conditions such as conn...

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Problems solved by technology

[0003] The purpose of a wellhead back pressure automatic control system provided by the present invention is to overcome the lack of complete equipment in the wellhead pressure controlled drilling operation implemented in the water injection area of ​​Changqing Oilfield in the prior art, which is only limited to normal drilling conditions, to realize The control of the wellhead back pressure cannot satisfy the wellhead back pressure control in working conditions such as connecting a single root and tripping out of the hole, and cannot realize the problem of wellhead pressure controlled drilling in the whole process; The pressure control equipment can meet the requirements of the whole process of pressure management drilling operations, but it has a lot of supporting equipment (back pressure compensation pump, PWD, flow metering system, automatic throttling manifold and central control system, etc.), and the pressure control system is complex (need to pass Bottomhole pressure monitoring, micro flow monitoring, etc.), high input cost, does not conform to the low-cost development strategy of Changqing Oilfield, and it is difficult to promote in the later stage

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