A directional drilling-exploring-monitoring integrated method for guaranteeing safety of an underwater shield tunnel includes: drilling a small-diameter borehole below a water area, and establishing an initial geological model; reaming the small-diameter borehole into a large-diameter borehole, placing a parallel electrical method (PEM) power cable and a monitoring optical fiber cable into the large-diameter borehole, acquiring zero field data, primary field data and secondary field data through carbon rod measurement electrodes before tunnel excavation, and processing the data with an existing inversion method to form an inversion image, thereby obtaining a refined geological model of a stratum; starting the tunnel excavation, and respectively acquiring a disturbance condition of rock and soil and a sedimentation and deformation condition of rock and soil around the tunnel during the excavation, thereby implementing safety excavation of the tunnel; and continuously monitoring the tunnel and the surrounding rock and soil in later use of the tunnel.

Estimating wear on bottom hole assembly (BHA) components utilizes a rock hardness index using analysis of drill cutting. Estimating the amount of wear on borehole assembly components comprises measuring the rock properties in drilled cuttings from a borehole. A hardness value is assigned to each mineral present in the drilled cuttings. A hardness index is calculated for a drilled borehole interval. A wear resistance factor is assigned to each BHA component of the BHA. The wear resistance factor depends on the wear resistance of each BHA component. A wear value for each BHA component is calculated based on the hardness index for the drilled borehole interval, the wear resistance of the BHA component, and drilling parameters.

A system to determine a contamination level of a formation fluid, the system including a formation tester tool to be positioned in a borehole, wherein the borehole has a mixture of the formation fluid and a drilling fluid and the formation tester tool includes a sensor to detect time series measurements from a plurality of sensor channels. The system includes a processor to dimensionally reduce the time series measurements to generate a set of reduced measurement scores in a multi-dimensional measurement space and determine an end member in the multi-dimensional measurement space based on the set of reduced measurement scores, wherein the end member comprises a position in the multi-dimensional measurement space that corresponds with a predetermined fluid concentration. The processor also determines the contamination level of the formation fluid at a time point based the set of reduced measurement scores and the end member.

A cutting tool with a cutting region and a connecting support region where the support region is designed to connect to an external motor assembly. The cutting tool is also has a porous region that is integrated within a portion of the tool such that as the tool cuts material the porous region can allow samples of the cut material to permeate into an internal chamber of the tool. Once in the internal chamber material samples can be analyzed in-situ for direct composition analysis.

A downhole sensor deployment assembly includes a body attachable to a completion string and one or more arms pivotably coupled to the body. A sensor pad is coupled to each arm and movable from a retracted position, where the sensor pad is stowed adjacent the completion string, and an actuated position, where the sensor pad is extended radially away from the completion string. One or more actuators are pivotably coupled to the body at a first end and pivotably coupled to a corresponding one of the one or more arms at a second end, the one or more actuators being operable to move the sensor pad to the actuated position. One or more sensor devices are coupled to the sensor pad for determining a resistivity of a formation, the one or more sensor devices comprising at least one of a sensing electrode, a transceiver, and a transmitter.

A flowback system and method employ a flowback model that characterizes fluid properties and rock mechanical properties of the reservoir during flowback in conjunction with measurement and analysis of chemistry and solids production with respect to the flowback fluid in order to maximize efficiency during the flowback operations, while mitigating formation damage and hydraulic fracture conductivity degradation. The methodology can define a safe drawdown operating zone for conducting flowback operations.

An embodiment of a method of performing aspects of a downhole operation includes receiving a measurement value from a first sensor configured to measure a parameter related to the downhole operation, receiving measurement data from a different sensor, the measurement data related to the downhole operation, and performing, by a sensor evaluation module, an evaluation of the first sensor. The evaluation includes determining a condition of the first sensor based on the measurement data from the different sensor, selecting a rule that prescribes a set of one or more measurement values of the parameter that are plausible if the condition is met, and determining whether the measurement value from the first sensor is plausible based on comparing the measurement value to the prescribed set of one or more measurement values.

Methods of analyzing the rock content of a geologic formation are provided herein. The methods typically comprise obtaining samples from the formation and subjecting the samples to conditions that will cause the extraction and/or release of one or more volatile compounds from the samples, if present in the samples, and then analyzing the amount of such one or more volatile compounds released/extracted from the sample and then further relating such results to the physical and/or rock content composition of two or more regions of the geologic formation. The results can be used to inform or guide oil and/or gas exploration and/or production operations, such as placement of fracking operations.

Systems and methods are provided for analyzing isotopes of a gas from a wellbore to determine geological information associated with the wellbore. A drill device can be used to drill rocks or particles in a wellbore, which can cause a gas to be released within the wellbore. Fluid can be pumped into the wellbore as the drill bit drills the rocks or particles and the fluid, along with the gas released, can flow through the wellbore and to a surface of the wellbore. A gas detector can be positioned near the wellbore for detecting an amount of gas and a type of gas in the fluid and gas mixture and transmitting data about the amount and type of the gas to a computing device. The computing device can output data based on the amount and type of gas in the mixture for determining geological information about the wellbore.

Analysis and logging of drilling mud using a mud analysis system and controlling drilling operations responsive to the mud analysis and logging. The system and methods may automatically sample and analyze drilling mud and control the drilling of a well responsive to the mud analysis. The mud analysis system may acquire measurements on a sample of the drilling mud during drilling and may send signals indicative of the drilling mud to a steering control system enabled to control the drilling.