Abstract

Hydrajet perforating (HJP) has been used in the oil industry for several decades to perforate or slot through casing by high-pressure abrasive jetting, which generally is not cost effective compared to conventional explosive (shaped-charge) perforating. However, within the Algerian oil fields, perforating using explosives has become time consuming and costly because of the strict security requirements associated with explosives. Operators commonly encounter delays in getting the explosives, varying from one week to one month, causing loss of production time and added standby costs for the rig and associated service equipment. Therefore, a nonexplosive solution like HJP has great value as an alternative to explosive perforating.

HJP, which forces highly pressured abrasives through jets to impinge/penetrate casing, cement, and formation, can be deployed on coiled tubing (CT) or jointed pipe. Typical penetration depths of 5 to 8 in. can be achieved, depending on the formation characteristics, tool configurations, pressure differential through the jet, and stand-off of the tool inside the casing. Perforation diameters from 0.75 to 3 in. have been achieved, as indicated by field tests and image logs run after perforating. This process has been developed and optimized for various applications, such as perforating for production, remedial cementing, or for hydraulic fracturing. It also has often shown advantages over explosive perforating, not only on a technical level but also from an economic perspective.

Therefore, hydrajet perforating is a valuable alternative to explosive-perforating techniques and does not require special authorizations for transportation and handling. This technique has benefited several operators in Algeria, saving cost and time, and also providing other advantages. This paper presents various applications of this technique and how it became an effective alternative to explosive perforating in several case histories from Algeria.

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