Systems and methods for an integrated wellbore stress, stability and strengthening analysis are disclosed. An integrated geomechanical tool can be used to analyze and evaluate stress along the length of the wellbore to identify a safe drilling mud weight window and help identify troublesome zones in the wellbore. Fracture length may then be predicted in the identified troublesome zones by using a stress tensor calculated during the stress analysis. The calculated fracture length may be used to perform a strengthening analysis. After performing strengthening analysis, mud loss may be predicted based on predicted fracture size calculated during the stress, stability and strengthening analyzes.

A method and a resistivity image logging tool connected or connectable to one or more processing devices process geological log data to construct missing information from destroyed or occluded parts using cues from observed data. The geological log data signals can be generated through use of the logging tool having one or more electrodes interacting with a formation intersected by a borehole. The processing involves the steps of: in respect of one or more data dimensions associated with missing values in a log data set, decomposing the signal into a plurality of morphological components; and morphologically reconstructing the signal such that missing values are estimated.

A method for injecting a portion of a drilling fluid waste into a well includes reducing a cross-sectional dimension of solids in a slurry. The slurry includes the drilling fluid waste. The method also includes measuring a property of the slurry, of the well, or both. The method also includes obtaining a model based at least partially upon the property. The model represents an interaction of the slurry with the well. The method also includes introducing an additive into the slurry in response to measuring the property, generating the model, or both. The method also includes injecting the slurry into the well after the additive is introduced.

Techniques for fracturing a subterranean formation penetrated by a wellbore are provided. The subterranean formation has vertical and horizontal stresses applied thereto. The wellbore has a near wellbore stress zone thereabout. The method involves drilling the wellbore along a drilling path (the wellbore having a vertical portion and a horizontal portion), creating at least one 360-degree perforation in the subterranean formation about the horizontal portions of the wellbore, and fracturing the formation by injecting a fluid into the 360-degree perforations. The 360-degree perforations extend about the wellbore a distance beyond the near wellbore stress zone and at least twice a diameter of the wellbore starting from an axis of the wellbore. A direction of the 360-degree perforation is transverse to the wellbore axis.

Techniques for determining a breakdown pressure of a subterranean formation include identifying in-situ stresses for a portion of a wellbore formed into a subterranean formation; transforming the in-situ stresses (and induced stresses) from a global coordinate system to a wellbore coordinate system of a deviated portion of the wellbore that includes at least one perforation tunnel for a hydraulic fracturing treatment; transforming the in-situ stresses from the wellbore coordinate system to a perforation coordinate system through at least one rotation matrix; determining one or more stresses at a wellbore-perforation interface of the perforation tunnel from the in-situ stresses in the perforation coordinate system; calculating one or more hoop stresses at a perforation tunnel wall of the perforation tunnel from the determined stresses on the wellbore-perforation interface; and determining a breakdown pressure for the subterranean formation based on the calculated one or more hoop stresses and an effect of casing-cement-formation interaction.

The present invention provides a shale gas well dynamic production allocating method. The steps comprise: step 1, constructing a single well material balance equation of a shale gas well; step 2, according to the actual shale gas well related reservoir properties, establishing the relationship function between the cumulative gas production and the formation pressure in combination with constructing a single well actual material balance equation in step 1; step 3, calculating the cumulative gas production according to the current formation pressure; step 4, through the productivity test, establishing a binomial productivity equation, and allocating production according to the open flow; step 5, according to the production allocating result obtained in step 4, drawing a chart of cumulative gas production and formation pressure and single well production allocation; and step 6, according to the cumulative gas production of different reservoirs of a shale gas well, searching for the resulting chart for production allocation. The solution of the present invention can not only quickly allocate production. In the production process of a gas well, according to the current cumulative gas production of the well, a reasonable production allocation amount can be quickly determined by searching for the chart, and there is no need to consider time factors in the production allocating process, which is very convenient, efficient, and practical.

The present invention discloses a method for evaluating and preventing creep damage to conductivity of hydraulic fracture in gas reservoirs, comprising: (1) selecting a rock sample of target reservoir for creep experiment, and plotting ε-t curve of the rock sample during creep; (2) fitting the fractional Kelvin model with the ε-t curve of the rock sample during creep; (3) calculating the conductivity and permeability of hydraulic fracture considering creep damage; (4) numerically solving the productivity model, calculating the cumulative gas production of the gas well produced up to time t, and calculating the creep damage rate for cumulative production of the gas well; (5) repeating Steps (3) to (4), calculating the creep damage rate for cumulative production for the cases of hydraulic fracture sanding concentration N of 5 kg/m.sup.2, 7.5 kg/m.sup.2, 10 kg/m.sup.2, 12.5 kg/m.sup.2 and 15 kg/m.sup.2 respectively, plotting the creep damage chart of cumulative production.

An innovative apparatus and computer implemented methods to obtain values for a set of scalars corresponding to each force and displacement, which may be obtained from acoustical signals captured by sensors of a drill bit while drilling, in a material of known mechanical properties, such as a cement from casing the well, such that the application and use of the scalars in relation to measurements of the mechanics while drilling, such as the acceleration of the bit and motion of the bit captured by sensors such as accelerometers, allow for absolute values of mechanical rock properties to be obtained in rock formations, being drilled through, with otherwise unknown mechanical properties prior to drilling.

Anisotropic elastic properties and subsequently in situ stress properties for a rock formation surrounding a wellbore are computed from rock physics and geomechanical models. Mineralogy data measured from DRIFTS on cuttings from the wellbore and rock physics and geomechanical models that have been log-calibrated in another wellbore are used in the computation. The method includes: (1) Defining and calibrating rock physics and geomechanical models using data from the first wellbore; (2) using DRIFTS analysis to measure mineralogy data on rock cuttings obtained through drilling operation in the second wellbore; and (3) using previously calibrated models to estimate in situ stress properties, including a stress index and the minimum principal stress magnitude.

A downhole investigation tool for a borehole is disclosed. The downhole investigation tool includes a number of ultrasonic probes configured to generate an ultrasonic image of a forward portion of the borehole ahead of the downhole investigation tool and a rear/side portion of the borehole behind or beside the downhole investigation tool, at least one magneto-vision probe configured to generate a magneto-vision image of the forward portion and the rear/side portion of the borehole, and a mechanical attachment configured to attach the downhole investigation tool to a wireline or a steel pipe in the borehole.