... properties. Results from this model show that the presence of small-scale heterogeneities in a sandstone has a dramatic impact on the acidizing process. Flow field heterogeneities cause acid to penetrate much farther into the formation than would occur if the rock were homogeneous, as is assumed by standard...

...J. M. Schembre; A. R. Kovscek The pore and grain surface of reservoir rocks often has clay and other fine material attached onto pore walls. It has been long recognized that brine salinity and pH are key factors affecting the attractive forces between pore surfaces and fines. If mobilized particles...

...T. Ohno; H. Karasawa, Mem. ASME; M. Kosugi; J. C. Rowley, Mem. ASME The authors have previously developed and proposed methods to estimate the in situ rock strength and tooth wear while drilling with roller-cone bits [Karasawa et al., 2002, ASME J. Energy Resour. Technol. 124, pp. 125–132 (Pt. 1...

..., Amsterdam. Aoki , T. , Tan , C. P. , and Bamford , W. E. , 1993 , “ Effects of Strength Anistrophy on Borehole Failures in Saturated Shale ,” Int. J. Rock Mech. Min. Sci. Geomech. Abstr. , 30 ( 7 ), pp. 1031 – 1034 . Ong , S. H. , and Roegiers , J.-C. , 1993 , “ Influence...

...Paolo Macini; Ezio Mesini Radioactive Marker Technique (RMT), an in-situ method to measure reservoir rock compaction and to evaluate uniaxial compressibility coefficients C m , is examined here. Recent field applications seems to confirm that RMT-derived C m ’ s match with sufficient precision...

... and their analysis becomes a problem. The paper presents mathematical models of the pressure-volume behavior for two different possible failures around the casing shoe, annular crack (cement-rock parting) and formation fracture. The study submits that these two failure modes would control abnormal LOT patterns...

...H. Karasawa; T. Ohno; M. Kosugi; J. C. Rowley, Mem. ASME New methods to estimate both the rock strength and tooth wear while drilling with roller-bits were developed and proposed in Part 1. These methods were derived from the results of drilling tests using milled-tooth type three-cone bits...

... surface materials and two different rocks over a wide range of normal stresses in up to four different fluids. Polished PDC cutters are shown to have lower frictional forces on the face of the cutter than standard cutters in both water and mineral oil. The measured friction coefficients were generally...

...H. Karasawa; T. Ohno; M. Kosugi; J. C. Rowley, Mem. ASME This paper proposes new methods to estimate both the rock strength and tooth wear while drilling with roller-bits. Laboratory drilling tests were conducted to obtain the penetration rate, bit weight and torque using milled-tooth bits...

...; revised manuscript received November 6, 2000. Associate Editor: A. Wojtanowicz. 26 February 1999 06 November 2000 cutting diamond stability rocks laboratory techniques testing Drillstrings are subjected to several types of vibrations. These vibrations take place...

... are computed from characteristic curves which are functions of the penetration of the bit into the rock and the angular velocity of the bit. Numerical simulations show self-excited oscillations of the drillstring, including bit take-off from the bottom hole and large amplitudes in the bit’s angular velocity...

...Yuri Melamed; Andrei Kiselev; Michael Gelfgat; Don Dreesen; James Blacic Percussion drilling technology was considered many years ago as one of the best approaches for hard rock drilling. Unfortunately, the efficiency of most hydraulic hammer (HH) designs was very low (8 percent maximum), so...