초록 ▼

An automatic cementing system and method are disclosed for precisely controlling the density of a slurry during a continuously mixed cement application. The system includes an input water line and a dry cement hopper for supplying water and dry cement, respectively, to a mixing chamber. The mixing c

An automatic cementing system and method are disclosed for precisely controlling the density of a slurry during a continuously mixed cement application. The system includes an input water line and a dry cement hopper for supplying water and dry cement, respectively, to a mixing chamber. The mixing chamber includes two chambers, Chamber A and Chamber B, for thoroughly mixing the water and cement together to form a cement slurry. Chamber B includes a level sensor for measuring the change in slurry level. The input line includes a pump for supplying the water to the mixing chamber, and a flow meter for measuring the rate at which the water is supplied. Similarly, the hopper includes a rotary valve for regulating the rate at which the dry cement is supplied to the mixing chamber and a speed sensor for measuring the speed of the rotary valve. A discharge line with a discharge pump and a discharge flow meter receives and discharges cement slurry. A recirculation line is included for density control during initialization. A system controller receives operational parameters from the operator, including desired slurry density, mix water density and dry cement density. Once the rate of the input pump is set, the controller monitors the output from the level sensor in Chamber B and adjusts the rotary valve until the level of slurry in Chamber B is constant. At that time, the amount of water leaving the system as slurry is calculated by the controller, and the controller then sets the rate of the input pump based upon this calculation.

대표청구항 ▼

A method for automatically controlling the density of a cement slurry in a system comprising a mix water input line, a dry cement hopper with a regulating valve, and a mixing chamber for mixing the water and cement to produce a cement slurry, including the steps of: (a) measuring the rate at which s

A method for automatically controlling the density of a cement slurry in a system comprising a mix water input line, a dry cement hopper with a regulating valve, and a mixing chamber for mixing the water and cement to produce a cement slurry, including the steps of: (a) measuring the rate at which slurry is discharged from the mixing chamber; (b) determining the percentage of water in the slurry; (c) calculating from steps (a) and (b) the rate at which water is being discharged; (d) setting the rate at which water is being input to the mixing chamber to be the same as the rate at which water is being discharged, as determined in step (c); (e) determining the percentage of dry cement in the slurry; (f) calculating from steps (a) and (e) the rate at which dry cement is being discharged; (g) setting an approximate rate of operation for the valve on said hopper to deliver dry cement at approximately the same rate as the rate at which dry cement is discharging from the mixing chamber, as determined in step (f); (h) adjusting the valve on said hopper in response to any change in slurry level in the mixing chamber.