A mixture of at least two shapes of a dissolvable diverter material. The shapes range from a flake having a high surface area to mass ratio to beads having a low surface area to mass ratio. The density of the various shapes may be manipulated by including voids or low-density materials within the shape. The density manipulation allows matching the transport properties of the at least two shapes to the transport fluid so that both shapes may arrive at the desired location at the desired time.

A settable down hole tool is of increased drillability and/or of increased expansibility. The improvement in drillability can be caused by fracturing cast iron slips into a large number of small pieces that can be circulated out of a well without further reduction in size. The improvement in expansibility can be partially caused by providing an expander cone of increased hardness thereby allowing an increased angle on the expander cone and slips. The improvement in expansibility can be partially caused by increasing the thickness of the slips.

A wellbore staged operation method, includes running, after a first well drifting operation is performed on a wellbore, a pipe string (100) in the wellbore, wherein the pipe string (100) includes, along a direction from bottom to top, a floating hoop (2), a plug seat (7), a toe-end sliding sleeve (3), and a fracturing sliding sleeve (4); performing a cementing operation, wherein cement slurry pumped into an inner chamber of the pipe string (100) enters an annulus between the pipe string and the wellbore through the plug seat (7) and the floating hoop (2) to form a cement sheath, the cement sheath isolating the toe-end sliding sleeve (3) from the fracturing sliding sleeve (4); performing a second drifting operation to ensure the toe-end sliding sleeve (3) of the pipe string (100) exposed; performing a pressure test for the pipe string; and performing staged fracturing constructions.

A method for drilling a geothermal well in a subterranean zone includes drilling, with a drill string, a wellbore of the geothermal well in the subterranean zone. An inherent temperature of the rock adjacent a rock face at a downhole end of the wellbore is at least 250° C. While drilling, a drilling fluid is flowed at a temperature at the rock face such that a difference between the inherent temperature of the rock adjacent the rock face and the temperature of the drilling fluid at the rock face is at least 100° C.

Methods of completing a hydrocarbon well. The methods include establishing a first fluid seal with an isolation device, forming a first perforation with a perforation device, and fracturing a first zone of a subsurface region with a pressurizing fluid stream. The methods also include moving the isolation device and the perforation device in an uphole direction within a tubular conduit of a downhole tubular that extends within a wellbore of the hydrocarbon well. Subsequent to the moving, the methods further include repeating the establishing to establish a second fluid seal, repeating the forming to form a second perforation with the perforation device, and repeating the fracturing to fracture a second zone of the subsurface region.

Method is provided for preventing fluid from entering a well, such as a producing well, during a hydraulic fracturing treatment in another well completed in the same reservoir. Degradable ball sealers or degradable particulate material is injected into the well and pressure is maintained in the well during the fracturing treatment to prevent influx of fluid.

A particulate plugging agent, such as a diverting agent and/or loss circulation material, using a particular polyvinyl alcohol with a certain amount of monovalent metallic salt, which is water-soluble and has a buffer effect even if the environment is acidic, and thus stable, which in particular finds use in various subsurface oil production operations.

The present invention discloses a method for realizing uniform stimulation for the oil and gas well by low-cost multi-stage fracturing, comprising the following steps: first calculate and predict the inlet widths of the fracture created in the planned hydraulic fracturing; then design the plugging scheme for blocking the fracture inlet after each fracturing treatment; the selected plugging particles are composed of filling particles and skeleton particles, with designed plugging scheme; after complete the design of plugging scheme, perform the fracturing treatment to create hydraulic fracturing in the reservoir; skeleton particles and filling particles are added into the fractures successively according to plan. The present invention provides a multi-stage single-cluster fracturing method, with the advantages of controllable fracture sizes and low cost. The present invention can realize a good uniformity of stimulation for the oil and gas wells.

The present invention discloses an optimized design method for a temporary blocking agent to promote uniform expansion of fractures produced by fracturing in horizontal wells, which comprises the following steps: calculating a particle size and a volume range of a candidate temporary blocking agent in an applicable target area; establishing a hydraulic fracture expansion calculation model with complete fluid-solid coupling; calculating an optimal average particle size required for effective temporary blocking; determining the particle size distribution of the temporarily blocked particles according to the optimal average particle size; calculating the particle volume of the temporary blocking agent required for effective temporary blocking; and predicting and evaluating a fracturing effect after the preferred temporary blocking design is adopted in the target area. The optimized design method for the temporary blocking agent to promote uniform expansion of fractures produced by fracturing in horizontal wells is used for improving the uniformity of fracture development of staged multi-cluster fracturing in horizontal wells, and has practicability and accuracy.

Provided is a frac window system, a well system, and a wellbore stimulation method. The frac window system, in one aspect, includes an elongated tubular having a first end and a second end with an opening defined in a wall of the elongated tubular between the first end and the second end, the wall having an inner surface and an outer surface, wherein the opening in the wall is configured to align with a window of a wellbore casing. The frac window system, according to this aspect, may further include a polished bore receptacle coupled to the first end of the elongated tubular, the polished bore receptacle having an inside diameter (ID.sub.1) sufficient to engage with a high-pressure frac string.