Atlantic Richfield Company

Yih-Min Jan

Paul R Paslay

Frank J Schuh

Carl T Montgomery

Amjad A Bseisu

A system and method for matrix stimulation field monitoring providing real time control, optimization and post job evaluation of matrix treatments is disclosed herein. Using calculated or measured bottom hole pressures or coil tubing reflective pressures, the system and method predicts pre-treatment damage or skin from a step rate test, then shows the evolution of skin removal versus treating fluid volume in real time. The method and system provides real time information about diverter use, treatment height, damage radius and other important well parameters.

Method for real time process control of well stimulation

Lateral vibrations of drillstring bottom hole assemblies are confirmed by sensing longitudinal and torsional accelerations or displacements of the drillstring at or near its top end during rotation and determining the lateral critical speed and displacement of the drillstring from the mode shape of the bottom hole assembly which occurs during forward synchronous whirl and longitudinal shortening of the bottom hole assembly resulting from such whirl. Lateral motion of the bottom hole assembly, while drilling, is estimated based on longitudinal and torsional measurements at the top of the drillstring. Radial displacement of the bottom hole assembly due to impacting of the borehole wall imparts a torsional impulse which, together with considerable radial motion, is repeated each revolution. The lateral or radial motion causes a small axial motion to develop in the bottom hole assembly which results in an axial force on and axial shortening of the drillstring which varies once per revolution.

Method of determining drillstring bottom hole assembly vibrations

A drillstem loading and behavior measurement method and system includes spaced apart subs disposed at the upper end of the drillstem and connected to each other and to a power or conventional swivel and having strain gages and accelerometers mounted thereon in such a way as to measure axial loading, axial vibration, torsional loading, torsional vibration and bending modes of the drillstem during operation. Accelerometers are mounted on respective ones of the subs at a distance from each other sufficient to determine vibration waveforms in axial, torsional and bending modes.

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Plano, TX, United States of America

Yih-Min Jan