Method of dynamic and variable parameter well-killing technology

Abstract

The invention provides a method of dynamic and variable parameter well-killing technology, belonging to the field of safe well-drilling. The method comprises the following steps: (1) obtaining basic parameters during a well-drilling process; (2) calculating formation pressure and gas cut rate according to the basic parameters; (3) configuring two well-killing fluids with different densities according to a result of the step (2) and determining volumes of well-killing fluids with different densities; (4) performing positive-cycle well-drilling operation: adopting two well-killing fluids with different densities to perform well-killing operation. During a well-killing process, casing pressure, standpipe pressure and circulating displacement are adjusted in a dynamic and real-time manner. Themethod is easy in realization and good in well killing effect and can quickly reduce the risk of excessively high well head pressure. Compared with a conventional well-killing method, the method enjoys high success rate and can meet the requirement for safe well-killing operation in a high-temperature high-pressure deep well during gas cut.

Description

technical field [0001] The invention belongs to the field of safe drilling, and in particular relates to a dynamic parameter-variable well killing process, which is used for the safety control and discharge of compressed gas invasion and overflow when gas invasion and overflow occur in the drilling process of high-pressure gas wells. Background technique [0002] With the increasing demand for oil and gas resources in my country's economy and society, oil and gas exploration and development are gradually moving towards deep complex reservoirs. For example, the deep formations of Sichuan Basin and Tarim Basin contain rich oil and gas resources. Due to the ultra-deep burial of resources in these areas, the ultra-high pressure and temperature at the bottom of the well, a series of drilling problems have been caused, especially the problem of well control safety. [0003] For deep-buried marine carbonate reservoirs, the reservoir space is mostly pores and fractures, gas-liquid r...

AI Technical Summary

Problems solved by technology

At present, the commonly used well killing methods mainly include engineer method, driller method, pressure back method, etc. They have the following problems: (1) In the killing process of ultra-deep wells, when the driller method is used in the first cycle of well killing, the wellhead pressure is high and out of control The risk is high; (2) The traditional engineer method uses a single-density well-killing fluid for operation. For deep wells and ultra-deep wells with narrow density window well-killing operations, the cycle killing time is long, and downhole losses and secondary overflows are likely to be caused during the well killing process. Complicated situations; (3) During the well killing process of the pressure back method, an overly high-density well killing fluid is usually used to kill the well, which is not conducive to reservoir protection. After repeated pressure back, the formation pressure is likely to be too high, and subsequent drilling is difficult

[0004] With the continuous increase of deep and ultra-deep well drilling, especially in the drilling process of carbonate reservoirs, frequent gas-liquid replacement and high risk of overflow well control, the traditional killing method can no longer meet the requirements of safe well killing of deep and ultra-deep wells

Images