A method for evaluating induced fractures in a wellbore includes obtaining a first set of data in a wellbore using a downhole tool. The method also includes pumping a first proppant into the wellbore after the first set of data is obtained. The first proppant includes a first tracer that is not radioactive. The method also includes pumping a second proppant into the wellbore. The second proppant includes a second tracer that is not radioactive. The second tracer is different than the first tracer. The first proppant and the second proppant flow into fractures in the wellbore. The method also includes obtaining a second set of data in the wellbore using the downhole tool after the first and second proppants are pumped into the wellbore. The method also includes comparing the first and second sets of data.

A system disclosed herein is for determining position of a distal end of a tubular string in a wellbore formed in a subsurface formation. The system includes casing lining the wellbore, with the casing carrying a plurality of radioactive sources. A tubular string is disposed in the wellbore and carries a radiation sensor along a length thereof. A processor is associated with the radiation sensor, and is configured to measure intensity of radiation received from the plurality of radioactive sources, and determine the position of the distal end of the tubular string by correlating a formation or wellbore fluid property that varies as a function of position within the wellbore and the measured intensity of the radiation received from the plurality of radioactive sources.

Methods and systems for depth and radial orientation detection are provided. Methods for determining the depth or radial orientation of one or more downhole components include the steps of providing a target mass and a using a detection device for detecting the depth and/or orientation of the target mass. In some cases, the target mass is initially nonradioactive and then, after installing the target mass downhole, it may be irradiated to form a relatively short-lived radioactive target mass, which may then be detected with a radiation detector. In this way, the target mass acts as a depth or radial orientation marker. Where the target mass is situated downhole in a known radial relationship to another downhole component, the radial orientation of the other downhole component may be deduced once the radial orientation of the target mass is determined. Advantages include higher accuracies and reduced health, safety, and environmental risks.

Methods, systems, and apparatuses for determining the location or depth in a wellbore of a tubular string or downhole component is provided. One method may include placing a tubular string having a depth measurement module into a wellbore, the wellbore emanating radiation at at least one location along the wellbore and determining the location of the depth measurement module in the wellbore based on a correlation between a wellbore property that is a function of depth and a radiation intensity at at least one location within the wellbore.

A borehole fluid imaging system includes a plurality of radiation sources located circumferentially around the borehole. A plurality of radiation detectors are located circumferentially around the borehole. The plurality of radiation detectors detect the radiation transmitted by each of the respective ones of the plurality of radiation sources. A controller is coupled to the plurality of radiation detectors to determine an attenuation of the radiation at the plurality of detectors and generate an image of the fluid in response to the attenuation of the radiation.

A borehole fluid imaging system includes a plurality of radiation sources located circumferentially around the borehole. A plurality of radiation detectors are located circumferentially around the borehole. The plurality of radiation detectors detect the radiation transmitted by each of the respective ones of the plurality of radiation sources. A controller is coupled to the plurality of radiation detectors to determine an attenuation of the radiation at the plurality of detectors and generate an image of the fluid in response to the attenuation of the radiation.

Disclosed are systems and methods for positioning of downhole tools via radioactive tag detection. The method comprises positioning a radiation detector at a first position within a wellbore, logging radiation data while the radiation detector is moved from the first position to a position adjacent to or past a radioactive marker disposed within the wellbore, determining, based on the radiation data, a time at which the radiation detector is adjacent to the radioactive marker, and calculating, based on the time, a distance between the first position of the radiation detector and the radioactive marker.

A logging device and method for locating a watered zone in a horizontal well with high watercut problem by isotope labeling is provided. The method successively includes the following operations: a. solidifying an isotope used in an isotope releasing device into a water-soluble carrier; b. connecting the isotope releasing device with a tubing and setting them to a horizontal segment of the well; c. dissolving the water-soluble carriers in the water at the bottom of the well to release the isotope, wherein the releasing rate is proportional to the flow rate of the water; d. starting a lift-up pump and beginning a production logging; and e. continuously performing -ray energy-spectrum analysis on produced water on the ground, so as to locate the watered zone of the horizontal well by the detected species and characteristic content of the isotope, thereby reduces operation risk, saves platform occupying time and logging cost.

A method for evaluating induced fractures in a wellbore includes obtaining a first set of data in a wellbore using a downhole tool. The method also includes pumping a first proppant into the wellbore after the first set of data is obtained. The first proppant includes a first tracer that is not radioactive. The method also includes pumping a second proppant into the wellbore. The second proppant includes a second tracer that is not radioactive. The second tracer is different than the first tracer. The first proppant and the second proppant flow into fractures in the wellbore. The method also includes obtaining a second set of data in the wellbore using the downhole tool after the first and second proppants are pumped into the wellbore. The method also includes comparing the first and second sets of data.

A method for evaluating induced fractures in a wellbore includes obtaining a first set of data in a wellbore using a downhole tool. The method also includes pumping a first proppant into the wellbore after the first set of data is obtained. The first proppant includes a first tracer that is not radioactive. The method also includes pumping a second proppant into the wellbore. The second proppant includes a second tracer that is not radioactive. The second tracer is different than the first tracer. The first proppant and the second proppant flow into fractures in the wellbore. The method also includes obtaining a second set of data in the wellbore using the downhole tool after the first and second proppants are pumped into the wellbore. The method also includes comparing the first and second sets of data.