NEW TECHNOLOGIES
CONTINUOUS CIRCULATION SYSTEM, CCS
Ahmed H. Abdul’aal
Faculty of Petroleum Engineering Suez Canal University
On connecting and disconnecting drill pipes, various problems may arise. For example: Disturbing the stability of the pressure downhole and thus taking a possible kick.
Industrial obstacles and challenges are demeaned everyday by the virtue of new technological advances and engineering breakthroughs. The role of those wonder solutions is increasing with a head spinning speed. The mark of a true successful engineer is to always be up to date, tirelessly catching up with a firm steady grip to every work-related cutting edge invention and time saving outbreak.
The scientific principle of continuous circulation is maintaining a constant ECD (Equivalent Circulating Density) at a level not exceeding the pore fracture gradient. It refers to the concept of allowing mud to continuously flow and circulate downhole while simultaneously connecting drill pipe. Previously, the conventional method required the mud flow to be paused as the new drill pipes were added, which disrupts the stability of the downhole pressure.
Pressure Drilling package. The CSS being a successful technology reduces the total connection time by 75%, enables continuous cuttings transport and optimizes the solids control processes. Moreover, it enables other technologies to be used, such as True Underbalanced Drilling (UBD), Liner Drilling and narrow pore pressure/frac-gradient drilling.
CCS is a self-contained rig floor device which allows drill pipe connections to be assembled, while drilling or tripping, without stopping circulation to the wellbore. It also provides a safe, reliable means of maintaining a constant steadily circulating downhole pressure environment. Most importantly, drilling with CCS enables wells to be drilled to the targeted depth in addition to allowing previously unattainable reservoirs to be accessed. Using the CCS requires no changes or additions to the drill string and all tool joint connect/disconnect operations at circulating pressure take place inside a pressure vessel constructed from proven BOP components. It can be used with open annulus mud returns or with rotating BOP equipment as part of a Managed
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January 2010
ECHO
Other features provided by CSS include reduced shallow water flows problems, elimination of ballooning effects, drilling difficult formations and finally reduction of kicks and stuck pipe incidents.
