A method for obtaining a maximum horizontal stress at a depth of a geological formation, includes: setting an estimate S.sub.Hmax of the maximum horizontal stress; conducting an elastoplastic modeling simulation of the geological formation around a wellbore with the estimate S.sub.Hmax and obtaining a simulated value ϕ.sub.b,1 of a breakout angle, wherein the breakout angle is a half-width of a breakout region; and upon determining that the estimate ϕ.sub.b,1 is greater than or equal to a prescribed value and is different from a measured breakout angle ϕ.sub.b,m at the depth by more than a threshold value, repeatedly changing the estimate S.sub.Hmax and conducting the elastoplastic modeling simulation.

A telescopic drill rod has at least two rod members disposed coaxially to one another, with the inner rod member being axially slidable relative to the outer rod member in a telescoping manner between an extended position and a retracted position. Both the inner rod member and outer rod member are equipped with joints at each end for connection to a drill head and/or another section of drill pipe. The joints also lock the inner and outer rod members in either the extended or retracted positions, and this is accomplished with a unique frusto-conical threaded engagement that is well-suited for transmitting pressure forces.

A telescopic drill rod has at least two rod members disposed coaxially to one another, with the inner rod member being axially slidable relative to the outer rod member in a telescoping manner between an extended position and a retracted position. Both the inner rod member and outer rod member are equipped with joints at each end for connection to a drill head and/or another section of drill pipe. The joints also lock the inner and outer rod members in either the extended or retracted positions, and this is accomplished with a unique frusto-conical threaded engagement that is well-suited for transmitting pressure forces.

The disclosure belongs to the technical field of engineering construction, and particularly relates to a square pile construction method and equipment of a rotary drilling rig. The specific technical solution concerns a square pile construction method of a rotary drilling rig which includes: site leveling; surveying and setting out; creating concrete retaining wall of wellhead; putting the drilling rig in place; adjusting the verticality of the drilling rig; lead hole drilling; reamed hole drilling; square hole drilling; hole cleaning with round drill bit; and hole cleaning with square drill bit. The square pile construction method and rotary drilling rig can use equipment for square pile construction in the whole process, effectively reduce the underground operation of laborers, and avoid the project safety production risk from the source. The disclosure also provides three kinds of square pile drill bits and a square pile hole cleaning drill bit in cooperation with the square pile construction method, which further realizes the mechanization of the whole process of square pile construction.

The present invention relates to a technique for identifying geological and drilling patterns by analyzing data from drilling parameters, using periodic orthogonal functions applied to such data. The use of averages to convert time data to depth data acts as a low-pass filter, attenuating the textural information from the torque data. Therefore, with the use of simple statistical filters combined with the use of multidimensional data visualization methods, it is possible to discretize drilling and geological patterns in the depth data acquired, aiding in the characterization of the top of the pre-salt carbonate reservoir, minimizing the geological and engineering risk in these operations. It is noted that in some situations of well kill, it is common not to have perceptible contrasts when analyzing the drilling parameters in the transition between the basal anhydrite and the carbonates, with the use of techniques such as PCA (Principal Components Analysis) being necessary in order to increase the method's power of discrimination. The technique disclosed minimizes the exploratory risks in pre-salt kill situations, as it allows precise characterization of the top of the carbonate reservoir.

A method of fracturing may comprise: varying a plurality of operational parameters of wellbore servicing equipment; observing a response of the wellbore servicing equipment; generating a model of the wellbore servicing equipment based on the response; and changing at least one of the plurality of operational parameters based at least in part on the model.

The disclosure presents processes and methods for decomposing friction factors and generating a calibrated friction factor and adjusted input parameters. The calibrated friction factor and adjusted input parameters can be utilized by a borehole system as an input to adjust borehole operations to improve the operational efficiency. The friction factors can be decomposed by type, such as geometrical, geomechanical, mechanical, and fluid. The disclosure also presents processes and methods for identifying an outlier portion of a friction factor, as identified by a deviation threshold that can be used to identify adjustments to borehole operations in that portion of the borehole. A system is disclosed that is capable of implementing the processes and methods in a borehole operation system, such as a downhole system, a surface system, or a distant system, for example, a data center, cloud environment, lab, corporate office, or other location.

A new system for and a method of deploying a heat exchanger pipe. A bore hole is drilled from an access ditch location to a terminal ditch location using a piloted drill head powered via an umbilical attached to the piloted drill head. A casing is attached to the piloted drill head and disposed about the umbilical into the bore hole from the access ditch location to the terminal ditch location. At the terminal ditch location, the piloted drill head is removed from the casing and the umbilical and a heat exchanger pipe is attached to the umbilical. The umbilical is withdrawn from within the casing deployed in the bore hole to pull the heat exchanger pipe into the casing. The casing is then withdrawn from the bore hole leaving the heat exchanger pipe in the bore hole.

A new system for and a method of deploying a heat exchanger pipe. A bore hole is drilled from an access ditch location to a terminal ditch location using a piloted drill head powered via an umbilical attached to the piloted drill head. A casing is attached to the piloted drill head and disposed about the umbilical into the bore hole from the access ditch location to the terminal ditch location. At the terminal ditch location, the piloted drill head is removed from the casing and the umbilical and a heat exchanger pipe is attached to the umbilical. The umbilical is withdrawn from within the casing deployed in the bore hole to pull the heat exchanger pipe into the casing. The casing is then withdrawn from the bore hole leaving the heat exchanger pipe in the bore hole.

A spindle with a mechanism for transferring axial force from an inner drive assembly to an outer drive assembly. The spindle's inner drive shaft is connected to an inner member of a dual-rod pipe by a drive rod having a sliding sleeve. The sleeve is fixed rotationally with the drive shaft, but not axially. When axial force drives the drive rod toward the drive member of the spindle, the sleeve contacts a stop member which is paired to the outer drive assembly. The stop member may be a pair of dowel pins. Axial force is thereby transferred from the inner member to the outer member, allowing such forces to be absorbed by the outer member's larger drive components.