An arrangement for visually identifying cuttings from different stages in a well is provided. In aspects of the disclosure, plugs may have different markers according to their respective position in a well, thereby allowing operators to visually identify locations in a well.

An arrangement for visually identifying cuttings from different stages in a well is provided. In aspects of the disclosure, plugs may have different markers according to their respective position in a well, thereby allowing operators to visually identify locations in a well.

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.

An apparatus and method for downhole measurement during operation of a drilling system is disclosed. The apparatus (30) comprises: a first sensor (302) configured to detect a property of a subsurface formation (200); a radiation source (304) configured to, when triggered, emit radiation to excite a part (220) of the formation; a processing unit (308) configured to trigger the radiation source if a change of the property of the formation is detected; a second sensor (306) positioned at a known distance from the radiation source and operably connected to the processing unit, the second sensor is configured to detect said excited part of the formation and is more distant from a drill bit (104) of the drilling system than the radiation source is; the processing unit is further configured to, after the excited part of the formation is detected, calculate a rate of penetration of the drill bit based on the following: a time duration between the radiation source is triggered and the excited part of formation is detected, and the distance between the radiation source and the second sensor.

An apparatus and method for downhole measurement during operation of a drilling system is disclosed. The apparatus (30) comprises: a first sensor (302) configured to detect a property of a subsurface formation (200); a radiation source (304) configured to, when triggered, emit radiation to excite a part (220) of the formation; a processing unit (308) configured to trigger the radiation source if a change of the property of the formation is detected; a second sensor (306) positioned at a known distance from the radiation source and operably connected to the processing unit, the second sensor is configured to detect said excited part of the formation and is more distant from a drill bit (104) of the drilling system than the radiation source is; the processing unit is further configured to, after the excited part of the formation is detected, calculate a rate of penetration of the drill bit based on the following: a time duration between the radiation source is triggered and the excited part of formation is detected, and the distance between the radiation source and the second sensor.

An apparatus and method for downhole measurement during operation of a drilling system is disclosed. The apparatus (30) comprises: a first sensor (302) configured to detect a property of a subsurface formation (200); a radiation source (304) configured to, when triggered, emit radiation to excite a part (220) of the formation; a processing unit (308) configured to trigger the radiation source if a change of the property of the formation is detected; a second sensor (306) positioned at a known distance from the radiation source and operably connected to the processing unit, the second sensor is configured to detect said excited part of the formation and is more distant from a drill bit (104) of the drilling system than the radiation source is; the processing unit is further configured to, after the excited part of the formation is detected, calculate a rate of penetration of the drill bit based on the following: a time duration between the radiation source is triggered and the excited part of formation is detected, and the distance between the radiation source and the second sensor.

An apparatus and method for downhole measurement during operation of a drilling system is disclosed. The apparatus (30) comprises: a first sensor (302) configured to detect a property of a subsurface formation (200); a radiation source (304) configured to, when triggered, emit radiation to excite a part (220) of the formation; a processing unit (308) configured to trigger the radiation source if a change of the property of the formation is detected; a second sensor (306) positioned at a known distance from the radiation source and operably connected to the processing unit, the second sensor is configured to detect said excited part of the formation and is more distant from a drill bit (104) of the drilling system than the radiation source is; the processing unit is further configured to, after the excited part of the formation is detected, calculate a rate of penetration of the drill bit based on the following: a time duration between the radiation source is triggered and the excited part of formation is detected, and the distance between the radiation source and the second sensor.

The present disclosure describes depth correlation tools and associated methods which do not require wireline depth correlation runs.

The present disclosure describes depth correlation tools and associated methods which do not require wireline depth correlation runs.