US 5,635,712 A · Method for monitoring the hydraulic fracturing of a subterranean formation

Abstract

A method for real-time monitoring of fracture extension during a fracturing treatment of a producing subterranean formation. A radioactive tracer injector is coupled to and spaced from a gamma ray detector by a distance approximately equal to a distance from a point of injection during fracturing to a boundary between the desired interval to be fractured and an adjacent formation which it is desired not to fracture. A programmed central processing unit positioned at a surface location receives spectral signals generated by the gamma ray detector during the fracturing treatment and generates a fracture penetration signal and a fracture injection pump control signal that stops a fracture injection pump whenever the fracture extension signal indicates the presence of radioactive tracer material within the producing subterranean formation at the depth location of the gamma ray detector. The programmed central processing unit distinguishes between the presence of radioactive tracer material within the formation versus radioactive tracer material within the borehole itself.

Claims28

Dependent claims

A method for monitoring the hydraulic fracturing of an earth formation traversed by a well borehole, comprising:

pumping a fracturing fluid into said formation at a first predetermined depth in said borehole to hydraulically fracture said formation;
conveying a tracer material down said borehole in a sealed container, said container including a means for selectively introducing said tracer material into a fluid, said tracer material including at least one tracer element;
introducing said tracer material into said fracturing fluid at a depth in said borehole proximate said first predetermined depth;
monitoring gamma radiation from said tracer material at a second predetermined depth in said borehole during said pumping, wherein said second predetermined depth is determined in reference to a depth in said borehole beyond which formation fractures are desired to not extend;
and
processing said monitored gamma radiation to distinguish between a presence of said tracer material within said borehole and a presence of said tracer material within said formation.

3 more elements

A method for monitoring the hydraulic fracturing of a subterranean formation traversed by a well borehole, comprising:

fracturing said subterranean formation by pumping a mixture of a fracturing fluid and a proppant to create hydraulic pressure on said formation at a predetermined fracturing depth within said borehole;
conveying a radioactive tracer material down in a sealed container proximate to said predetermined fracturing depth, said container containing means for injecting said tracer material into said fracturing fluid;
detecting a gamma ray spectrum of said radioactive tracer material at a first predetermined depth in said borehole while said mixture is being pumped;
processing said gamma ray spectrum detected at said first predetermined depth to determine a presence of said radioactive tracer material within said borehole and said presence of said radioactive tracer material within said subterranean formation at said first predetermined depth;
and
stopping said fracturing of said subterranean formation when said presence of said radioactive tracer material is determined within said subterranean formation at said first predetermined depth.

3 more elements

A method for monitoring the hydraulic fracturing of a subterranean formation traversed by a well borehole, comprising:

conveying radioactive tracer material in a container down said borehole to a predetermined fracturing depth within said borehole, said container including means for infecting said radioactive tracer material into a fluid;
fracturing said subterranean formation by pumping a mixture of particles and fluid into said subterranean formation to create hydraulic pressure on said subterranean formation at a predetermined fracturing depth within said borehole;
injecting said radioactive tracer material into said mixture at said predetermined fracturing depth;
detecting a first gamma ray spectrum of said radioactive tracer material at a first predetermined depth while said mixture is being pumped;
detecting a second gamma ray spectrum of said radioactive tracer material at a second predetermined depth while said mixture is being pumped;
processing said first detected gamma ray spectrum to determine a presence of said radioactive tracer material within said subterranean formation and to distinguish between a presence of said radioactive tracer material within said borehole and said presence of said radioactive material within said subterranean formation at said first predetermined depth by means of a predetermined relationship between said first detected gamma my spectrum and a relative radial location of said radioactive tracer material;
processing said second detected gamma ray spectrum to determine a presence of said radioactive tracer material within said subterranean formation and to distinguish between a presence of said radioactive tracer material within said borehole and said presence of said radioactive tracer material within said subterranean formation at said second predetermined depth by means of a predetermined relationship between said second detected gamma ray spectrum and a relative radial location of said radioactive tracer material;
and
stopping said fracturing of said subterranean formation when said presence of said radioactive tracer material is determined within said subterranean formation at said first predetermined depth or at said second predetermined depth.

6 more elements

Dependencies are inferred from the claim text.

Method for monitoring the hydraulic fracturing of a subterranean formation

Life of this patent

Method for monitoring the hydraulic fracturing of a subterranean formation

Life of this patent

Abstract

Claims28