Robert W Swain

US Patent:

61422290, Nov 7, 2000

Filed:

Sep 16, 1998

Appl. No.:

9/154360

Inventors:

Aubrey G. Branson - Bakersfield CA
Michael Patrick Kelly - Bakersfield CA
Robert S. Swain - Plano TX

Assignee:

Atlantic Richfield Company - Chicago IL

International Classification:

E21B 4700
E21B 4300

US Classification:

16625015

Abstract:

A method and system for producing hydrocarbons from a low permeability formation through a well wherein the formation is first fractured with steam. The pressure of the produced fluids is measured at timed intervals and signals representative of these measurements are inputted into a computer which, in turn, calculates the rate of change in the pressure and compares this rate to a preferred limit of rate change. When the limit is exceeded, the computer outputs a signal to adjust a control value in the production line to keep the rate of pressure decrease within the preferred limit. When production drops below a certain level, the control valve is fully opened to "bump" the well and allow the pressure to increase to a new maximum. This new maximum pressure is then used to set a new preferred limit of pressure rate change.