A drilling method and a drilling apparatus are provided. In the method, the feature parameter of the stratum around the well, the feature parameter of the stratum in front of the drill bit, the preset drilling parameter, the preset trajectory parameter, the current pose of the drill bit and the current rate of penetration of the drill bit are obtained; the feature parameter of the reservoir in front of the drill bit is determined based on the feature parameter of the stratum around the well and the feature parameter of the stratum in front of the drill bit; the above parameters are inputted to the pre-trained drilling parameter modification model to obtain drilling trajectory parameter and drilling speed parameters; and the drilling direction and the rate of penetration are regulated based on the above parameters.

A risk assessment-based design method for a deep complex formation wellbore structure includes: (1) preliminarily determining casing layers and setting depths; (2) calculating to obtain the risk coefficients of each layer of casing; (3) analyzing and coordinating, according to the principle that a shallow casing shares more risks and a deep casing shares less risks, the risks of each layer of casing: determining whether the risk coefficients of each layer of casing are greater than a safety threshold value K; checking the setting depth: if the safety coefficient of an ith-layer casing satisfies R.sub.Ni>K, selecting a casing layer with the minimum safety coefficient from upper casing layers, and deepening the setting depth h of the casing layer; and (4) repeating the steps (2) to (3) until the casing risk coefficients of each layer of casing are less than the safety threshold value K.

A bottom hole assembly (BHA) includes a top sub-assembly configured to couple to a downhole conveyance to move into a wellbore that includes completion components secured in the wellbore; a drill bit configured to drill out and remove a first portion of a subset of the completion components; and an expandable reamer including a cutting assembly and configured to adjust between a retracted position in which a diameter of the cutting assembly is less than a diameter of a bore through at least one of the completion components and an activated position in which the diameter of the cutting assembly is greater than the diameter of the bore. The expandable reamer is further configured to remove a second portion of the subset of the completion components in the activated position.

Techniques for generating a geological model include identifying a plurality of well data for each of a plurality of wells drilled into a reservoir basin from a terranean surface. The reservoir basin includes a plurality of landing zones formed under the terranean surface, each of the landing zone including a discrete geological layer. The techniques further include comparing the plurality of well data for each well with a reservoir basin database that associates the well data with one of the plurality of landing zones; correlating each of the plurality of wells with a particular landing zone of the plurality of landing zones based on the comparison; and generating a geological model of the reservoir basin based on the correlated wells.

This invention is detailing a construction method for a cast in-situ pile having an upper section with a larger diameter and at least one subsequent section with a smaller diameter, and a drilling device equipped with continuous flights which allows the construction of one pile having multiple diameters using the innovative construction method in a single continuous drilling phase while each drilling tool is penetrating through the soil in one pass.

The drilling tool according to the invention has a central hollow space that allows accommodation through it of at least one another smaller diameter drilling tool that can drill continuously and can be coupled by means of a coupling-decoupling device in a specific manner to the other drilling tool in order to act as a fixed assembly, at any given position in relation to the smaller drilling tool length and rotating position.

Provided is a novel drilling apparatus for drilling into prepared ground surfaces and natural ground conditions. The apparatus includes a mast assembly, a support structure assembly flexibly coupled with the mast assembly, a plurality of drill assemblies affixed to the support structure assembly, and a frame. Also provided is a method of drilling into a ground surface, by providing a drilling apparatus having a mast assembly, a support structure assembly flexibly coupled with the mast assembly, a plurality of drill assemblies affixed to the support structure assembly, and a frame. Each of the drill assemblies include a hollow drill rod with a drill bit at one end, the bit having exterior cutting elements and interior fluid diverters. Pressurized fluid and torque is supplied to the drill rods, and by means of the mast assembly and support structure assembly the drill rods are moved downward so that using the downward and rotational force, and the pressurized fluid, the drill bits drill into the ground surface.

A system for monitoring and controlling downhole pressure of a well borehole relative to a lithostatic pressure of rock surrounding the borehole is provided. The system can include a millimeter wave drilling apparatus including a gyrotron configured to inject millimeter wave radiation energy into a borehole of a well via a waveguide configured for insertion into the borehole. The borehole can be formed via the millimeter wave drilling apparatus and having a downhole pressure monitored at a bottom of the well. The system can also include a compressor fluidically coupled to the borehole and configured to control the downhole pressure via a gas supplied into and/or received from the borehole. The compressor can be configured to control the downhole pressure relative to a lithostatic pressure determined for rock surrounding the well at the bottom of the well.

Geologic material in a borehole is weakened by accelerating a projectile into contact with the material. A drill bit is then used to bore through the weakened material. To accelerate the projectile, an endcap is placed in a conduit using a source of gas. The endcap isolates the conduit from the external environment. A projectile is then positioned in the conduit above the endcap. Movable members within the conduit are operated in sequence to enable single endcaps and projectiles to be moved into the conduit. Gas from the conduit is evacuated into an annulus between the conduit and a surrounding conduit, and a propellant material is provided into the conduit. The propellant material applies a force to the projectile to accelerate the projectile into contact with the geologic material. A fluid is circulated down a second annulus outside of the surrounding conduit to contact the drill bit and remove debris.

Systems and methods of surface steering control of drilling may be used together with systems and methods for planning one or more wells before drilling, planning a well path during drilling and/or updating that well plan and/or other well plans during the drilling of a well. The methods and systems may include planning a field, comprising a plurality of wells to be drilled and/or a plurality of pads from which a plurality of wells are to be drilled, planning a pad from which a plurality of wells are to be drilled, and planning a well both before and during drilling of the well.

A method for monitoring and controlling a downhole pressure of a well during formation of a borehole of a well is provided. The method can include monitoring a downhole pressure of a well during formation of a borehole of the well using a millimeter wave drilling apparatus including a waveguide configured for insertion into the borehole. The monitoring can include determining the downhole pressure. The downhole pressure can include an amount of pressure present at a bottom of the well. The method can also include determining a lithostatic pressure of rock surrounding the well at the bottom of the well. The method can further include controlling the downhole pressure relative to the lithostatic pressure of the rock surrounding the well at the bottom of the well. Related systems performing the methods are also provided.