Abstract: Systems, methods, and computer-readable media are provided for simulating the coupled axial/torsional dynamics of drilling systems.

Abstract: Systems, methods, and computer-readable media are provided for simulating the coupled axial/torsional dynamics of drilling systems.

Abstract: A method of predicting a well trajectory wherein the method utilises a series of parameters to calculate the trajectory. The method is characterised in that the parameters include the angle of a drill bit (23) relative to a well bore (27), and the variation of said angle during drilling wherein the variation of said angle is related to the moment on the bit (23).

Abstract: A method of predicting a well trajectory wherein the method utilises a series of parameters to calculate the trajectory. The method is characterised in that the parameters include the angle of a drill bit (23) relative to a well bore (27), and the variation of said angle during drilling wherein the variation of said angle is related to the moment on the bit (23).

Abstract: A portable apparatus (111) to measure the change in behaviour of a rock specimen (113) in a fluid (25) of prescribed composition. The rock specimen (113) is prepared from drill cuttings, wellbore cave-in material, or core offcuts returned during the drilling operation of a wellbore. The apparatus (111) comprises a vessel (23) in which the fluid (25) and specimen (113) are placed. The apparatus (111) has a loading means for applying at least one load upon the specimen (113) and at least one measuring device (119) to measure the deformation of the specimen (113) in response to a change in load. The apparatus (111) also comprises a stirring system to maintain uniformity of the fluid (25) and a temperature regulating device (131) to maintain the fluid (25) at the desired temperature.

Abstract: Solutions for the propagation of a hydraulic fracture in a permeable elastic rock and driven by injection of a Newtonian fluid. Through scaling, the dependence of the solution on the problem parameters is reduced to a small number of dimensionless parameters.

Abstract: Method and apparatus for estimating a fluid driven fracture volume during hydraulic fracturing treatment of a ground formation. A series of tiltmeters are positioned at spaced apart tiltmeter stations at which tilt changes due to the hydraulic fracturing treatment are measurable by those tiltmeters. Tilt measurements obtained from the tiltmeters at progressive times during the fracture treatment are analysed to produce estimates of the fluid driven fracture volume at each of those times as the treatment is in progress. The analysis may be performed sufficiently rapidly to provide real time estimates of the fluid driven fracture volume and may also produce estimates of fracture orientation. The estimates of fracture volume may be compared with the volume of fluid injected to derive an indication of treatment efficiency.

Abstract: Solutions for the propagation of a hydraulic fracture in a permeable elastic rock and driven by injection of a Newtonian fluid. Through scaling, the dependence of the solution on the problem parameters is reduced to a small number of dimensionless parameters.

Abstract: Solutions for the propagation of a hydraulic fracture in a permeable elastic rock and driven by injection of a Newtonian fluid. Through scaling, the dependence of the solution on the problem parameters is reduced to a small number of dimensionless parameters.

Abstract: Solutions for the propagation of a hydraulic fracture in a permeable elastic rock and driven by injection of a Newtonian fluid. Through scaling, the dependence of the solution on the problem parameters is reduced to a small number of dimensionless parameters.

Abstract: A portable frame that includes a movable support for supporting a cutting tool used for engaging a rock sample, and upon relative movement between the rock sample and the cutter, the cutter will make a constant depth cut at a constant velocity. During the cut, the forces parallel to the direction of displacement and perpendicular to the direction are measured, and both cohesion and internal friction angle, which are parameters characterizing the rock strength, the internal friction angle, which is a true measure of the rock strength, can be determined.

Abstract: A tool for measuring the mechanical properties of a formation through which a borehole has been drilled, comprising a tool body capable of being lowered into a borehole, the tool body having pads mounted on movable arms, each pad carrying a PDC type cutter which is urged against wall of the borehole so as to cut into the formation; transducers are provided for determining the depth of cut made by the cutter and for determining the resistance of the rock to cutting. The tool is connected to a wireline, enabling the cutter to be moved through the formation and the data from the transducers to be returned to the surface for analysing the depth of cut and resistance to cutting to determine the mechanical properties of the rock.

Abstract: This invention is based on a new model describing the drilling process of a drag bit and concerns a method of determining the drilling conditions associated with the drilling of a borehole through subterranean formations, each one corresponding to a particular lithology, the borehole being drilled with a rotary drag bit, the method comprising the steps of: measuring the weight W applied on the bit, the bit torque T, the angular rotation speed .omega. of the bit and the rate of penetration .nu. of the bit to obtain sets of data (W.sub.i, T.sub.i, .nu..sub.i, .omega..sub.i) corresponding to different depths; calculating the specific energy E.sub.i and the drilling strength S.sub.i from the data (W.sub.i, T.sub.i, .nu..sub.i, .omega..sub.i); identifying at least one linear cluster of values (E.sub.i, S.sub.i), said cluster corresponding to a particular lithology; and determining the drilling conditions from said linear cluster.