Waves from cement bond logging with a sonic logging-while-drilling tool (LWD-CBL) are often contaminated with tool waves and may yield biased CBL amplitudes. The disclosed LWD-CBL wave processing corrects the first echo amplitudes of LWD-CBL before calculating the BI. The LWD-CBL wave processing calculates a tool wave amplitude and a phase angle difference as the difference of the phases between the tool waves and casing waves. The tool waves are then used to correct the LWD-CBL casing wave amplitude and remove errors introduced from tool waves. In conjunction with the sets of operations described, the LWD-CBL wave processing also include array preprocessing operations. Array preprocessing may employ variation of bandpass filtering and frequency-wavenumber (F-K) filtering operations to suppress tool wave.

A method for steering a well based on rock properties and obtaining natural fracture information includes inducing tube waves in the well during drilling the well. Acoustic energy is measured in the well. The energy comprises tube wave reflections from formations adjacent to the well. The measured acoustic energy is inverted to determine at least one of a rock property, a near wellbore hydraulic conductivity, and natural fracture occurrence. A trajectory of the well is adjusted to maintain the at least one of a rock property, near wellbore hydraulic conductivity and natural fracture occurrence. An n optimized, well-customized hydraulic fracturing design may be created based on the measured natural fracture properties. A method to optimize hydraulic fracturing treatment based on measured natural fracture properties during drilling.

A modular system for analyzing drilled cuttings includes a sampler unit, a washer unit, an analysis unit, and a central processing unit. The sampler unit receives the drilled cuttings from a shale shaker disposed on a rig site that obtains the drilled cuttings. The washer unit removes debris from the drilled cuttings. The analysis unit determines lithological properties of the drilled cuttings. The packager unit packages the drilled cuttings. The central processing unit coordinates operations to process the drilled cuttings through each of the sampler unit, washer unit, analysis unit and packager unit. The central processing unit facilitates a processing link among the sampler unit, washer unit, analysis unit and packager unit so that the sampler unit, washer unit, analysis unit and packager unit are integrated to form the modular system.

A resistivity-measuring sensor disposable within a drillstring includes a sensor body having a longitudinal axis, wherein the sensor body is separable from and disposable in the drillstring at a radially offset distance from the longitudinal axis of the drillstring. The sensor further includes a transmitting antenna disposed along a length of the sensor body, a receiving antenna disposed along a length of the sensor body, and an electronics section contained within the sensor body for generating and receiving signals to and from the transmitting and receiving antennas.

A method of designing a cement blend for a wellbore isolation barrier based on the analysis of a stress state of the wellbore isolation barrier from the injection of CO.sub.2 into a porous formation. The analysis software may determine an optimized cement blend for a future CO.sub.2 injection schedule. The analysis software may determine a current near wellbore stress state for a current CO.sub.2 injection schedule. The analysis software may optimize a CO.sub.2 injection schedule based on the analysis of a future near wellbore stress state of the wellbore isolation barrier. The near wellbore stress state of the isolation barrier may be determined by at least one model accessed by the analysis software. The inputs into the model comprise periodic CO.sub.2 injection pressure and flowrate datasets, cement properties, and formation properties.

Embodiments are directed to managing and improving a drilling and completions process at a hydrocarbon extraction site, and to optimizing resource allocation at a hydrocarbon extraction site/region. In one scenario, a computer system accesses data generated by hardware sensors implemented by drilling and completion equipment at a hydrocarbon extraction site. The computer system formats the sensor data into a form readable by a data mining algorithm, and mines the formatted sensor data to identify characteristics related to the drilling and completion process. The computer system also accesses and integrates historical data related to the drilling and completion equipment at the hydrocarbon extraction site. The computer system then computes drilling and completion performance indicators that identify inefficiencies based on the characteristics identified for the equipment and based on the accessed historical data. Then, a remediation step is performed to resolve the identified inefficiency.

A downhole drilling system is disclosed. The system may include a drill bit including first and second electrodes electrically coupled to a pulse-generating circuit to receive pulse drilling signals, a reference sensor in proximity to the drill bit, an additional sensor uphole from the reference sensor, and a sensor analysis system communicatively coupled to the reference sensor and to the additional sensor. The sensor analysis system may be configured to obtain measurements representing responses recorded simultaneously by the reference sensor and by the additional sensor during a pulsed drilling operation in a wellbore, generate modified measurements in which effects of variations in the pulse drilling signal on the measurements representing responses recorded by the additional sensor are reduced based on the measurements representing responses recorded by the reference sensor and determine, based on the modified measurements, a characteristic of a formation downhole from the drill bit.

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.

A method includes deploying an optical fiber attached to a distributed acoustic sensing (DAS) interrogator in a wellbore, pre-setting gauge length of the DAS interrogator based on an expected measurement signal, interrogating the optical fiber using the DAS interrogator, receiving reflected DAS signals along a length of the optical fiber using the pre-set gauge length, performing an analysis to estimate a location and a magnitude of a strain source associated with the reflected DAS signals, and dynamically adjusting the gauge length for at least a portion of the optical fiber within a pre-defined limit of the DAS interrogator as a function of the estimated location and magnitude of the strain source to enhance sensitivity and to optimize signal-to-noise ratio.

The invention discloses a method for improving a recovery ratio of a braided well pattern of a hugely thick or multi-layer oil and gas reservoir, which improves the recovery ratio of the hugely thick or multi-layer oil and gas reservoir by designing the braided well pattern. The braided well pattern is designed through the following method: dividing a cubic development unit of the oil and gas reservoir; measuring a physical property parameter of the cubic development unit; calculating a well pattern design parameter according to the physical property parameter, wherein the well pattern design parameter includes a number of wells and a well bore track; and drilling a large-displacement horizontal well according to the well pattern design parameter. The step of dividing the cubic development unit of the oil and gas reservoir specifically includes: obtaining a boundary of the oil and gas reservoir through seismic volume data; obtaining a main layer series of development of the oil and gas reservoir according to a geological model established on the basis of a prospecting parameter; and establishing a cube with a largest volume in the main layer series of development, wherein the cube is the cubic development unit. The invention can effectively improve the recovery ratio of the hugely thick or multi-layer oil and gas reservoir.