An improved method in handling well control kick circulation

Abstract

Well control is the technique used in oil and gas operations such as drilling, well workover, and well completions to maintain the fluid column hydrostatic pressure and formation pressure to prevent influx of formation fluids into the wellbore. During drilling operations, the hydraulic pressure balance is the most important condition for maintaining a safe drilling environment. The influx from the formation is inevitable during the drilling process, and the formation fluid that goes into the wellbore will displace equal volume of drilling fluids out of the hole. In order to maintaining suitable hydrostatic pressure, it is necessary to circulate the kick out with a suitable method. The existing method of well control circulation is to monitor the drill pipe pressure and manage the choke to hold the bottom hole circulating pressure above formation pressure while circulating the influx out of the annulus. However, this heavily relies on the experience of the personnel particularly if problems occur. In order to circulate a kick out with a safe bottom hole pressure, usually the choke operator control chokes by observing stand pipe pressure, which was calculated on a kill sheet. One of the major disadvantages of the existing method is that the pressure wave needs a few seconds to travel from the choke which is located near the casing to the stand pipe pressure gauge. (If the pressure wave travels at 1000ft/s from the choke to standpipe, then the standpipe gauge response time required for a 10,000ft well would be 20 seconds) In order to avoid this pressure retard the choke operator could calculate and monitor the casing pressure on the control panel, and calculate the stand pipe pressure in addition. One of the major advantages of this method is that it enables the choke operator to handle the complicated downhole situation with more accuracy and immediate response. In addition, this method gives more accurate and timely detection of some of the well control problems such as Nozzle Plugging, Nozzle Washout Drill String Wash out, Choke Plug and Washout, etc. Well control problems such as nozzle and choke washout and plugging may lead to major well control issues if they are not detected in a timely way. This heavily relies on the experience of the personnel. There is a need to detect these problems in a timely way in order to avoid subsequent problems. The improved method presents a technique that does not rely on the experience of the personnel.

Date of Award	2012
Original language	American English
Supervisor	Ferda Akgun (Supervisor)