Abstract:
A method for locating planned markers within a log containing borehole data parses log data to locate an uncertainty region for a planned marker. A fingerprint match is located for the planned marker in the located uncertainty region. The located fingerprint match is saved. A determination is made if additional planned markers are present and returns to the step of parsing for a next planned marker if additional planned markers are present.
Abstract:
An inert (non-radioactive) tagging material can be added to cement in a wellbore. The non-radioactive tagging material can emit radiation at a specific energy level when irradiated with radiation. A logging tool containing a radiation source can be introduced into a wellbore and activated to emit radiation. The logging tool can detect the radiation emitted from the non-radioactive tags within the wellbore. Accordingly, integrity of cement, particularly low density cements that have a density close to that of fluid provided to or contained within a hydrocarbon-bearing formation, can be determined from the detected radiation.
Abstract:
A marker placement device, such as a modified coring gun, is used to place one or more markers into the formation. The marker placement device uses explosive charges to fire one or more marker assemblies into a borehole wall. A marker assembly includes a driver assembly which is adapted to be fired from the placement device and a marker which is releasably secured to the driver with frangible shear members.
Abstract:
A method for determining fracture geometry of a subterranean formation from radiation emitted from a fracture in the formation, including measuring gamma-radiation emitted from the fracture; subtracting background radiation from the measured gamma-radiation to obtain a peak-energy measurement; comparing the peak-energy measurement with a gamma-ray transport/spectrometer response model; and determining formation fracture geometry of the fracture in accordance with values associated with the response model.
Abstract:
A method for measuring the infiltration of coring fluid into a core sample taken from a formation comprises a) providing a coring fluid containing cesium in a first concentration, b) using the coring fluid and a coring means to generate the core sample, c) determining the concentration of cesium present in the core sample; and d) comparing the core sample cesium concentration to the first concentration. A further preferred step comprises using the comparison in step d) to calculate the degree of infiltration of the coring fluid into the core sample.
Abstract:
A process for treating naturally occurring radioactive material (NORM) comprises use of NORM as a mud constituent in a drilling mud manufacturing process and particle size reduction of the NORM particles during or before that process to attain a selected particle size corresponding to that of a particulate drilling mud component, said particle size reduction being optionally accompanied by additional mixing, if necessary, of the NORM and mud component particles, the aim of said use being the achievement of irreversible dilution of the NORM particles in said component to nullify the radioactive nature thereof.
Abstract:
A natural gamma tag marking materials for sub or permanent markers used in gamma logging operations, such natural gamma materials having a gamma count of between 200 and 1000 counts per second. The instant invention further discloses a typical Sub, for insertion in a drilling operation, utilizing natural gamma element compounds which are considered to be non-hazardous and effective as tag markers when used in wireline logging operations.
Abstract:
There is disclosed a casing centralizer which comprises a tubular body or sleeve adapted to fit about a joint of casing, and blades extending longitudinally along the outer diameter of the sleeve in generally equally spaced apart relation, with the body and blades being cast as one metal piece.
Abstract:
The present invention relates to a device for placing a radioactive source into a formation through which a borehole passes. The device includes a gun barrel, a bullet containing a radioactive source and engaged in the barrel, and an explosive device for propelling the bullet towards the formation. The device further includes two items which reduce the speed at which the bullet, when fired, penetrates into the formation. These items are a spacer, placed in the barrel between the bullet and the explosive device, and a braking shield placed at the port end of the barrel. The spacer reduces the effect of the gases produced by the explosive device upon detonation. The braking shield is entrained with the fired bullet, the front end of the shield producing drag which also acts to retard the forward propulsion of the bullet. The shield is designed to break away from the bullet upon formation impact, further reducing the kinetic energy of the bullet. The invention is applicable to soft formations.
Abstract:
Apparatus including a well logging tool and surface equipment provides an output substantially corresponding to the expected subsidence of a frozen earth formation upon thawing.