摘要:
A method for determining the characteristics of a subterranean formation penetrated by an existing or drilled well is disclosed. The method uses a mathematical model to estimate formation parameters as fluid exits the formation through a hole and into the wellbore or tool. The model may be adapted to wells having a perforation extending from the wellbore into the formation by mathematically adjusting the perforation to the hole of the mathematical model. The formation properties may be estimated by mathematically eliminating the perforation and replacing it with an enlarged hole radius to simulate the mathematical model.
摘要:
Methods and apparatus for detecting a coating on a downhole fluid sensor are disclosed. A coating may refer to a solid or liquid film on a sensor interface with the sampled fluid, caused by contaminants. Detecting a coating may be accomplished by determining a sampled fluid type and measuring at least one fluid parameter using one or more downhole fluid sensors. The coating detection further includes determining whether the measured parameters are within ranges corresponding to the determined fluid type. Additionally or alternatively, measured parameter values that remain substantially stable during sampled fluid pumping may also indicate a coated sensor.
摘要:
A method for determining permeability of a reservoir using a packer-probe formation testing tool. The elements of the method include generating, using a dual packer tool module, fluid flows from the reservoir into a wellbore, obtaining pressure data associated with the fluid flows using an observation probe tool module, wherein the packer-probe formation testing tool comprises the dual packer module and the observation probe tool module, identifying a portion of the pressure data corresponding to a spherical flow regime, determining horizontal permeability based on the portion of the pressure data, and displaying an output generated using the horizontal permeability.
摘要:
Example methods and apparatus to detect phase separation in downhole fluid sampling operations are disclosed. An example method to detect a phase separation condition of a fluid from a subterranean involves obtaining a sample of the fluid, measuring a first characteristic value of the sample, measuring a second characteristic value of the sample and comparing the first characteristic value to a first reference value associated with a single-phase condition of the fluid to generate a corresponding first comparison result. The example method then compares the second characteristic value to a second reference value associated with the single-phase condition of the fluid to generate a corresponding second comparison result and detects the phase separation condition of the fluid based on the first and second comparison results.
摘要:
A method of sampling fluid from a subterranean formation includes positioning a first tool having a heater in a borehole so that the heater is adjacent a portion of the subterranean formation; heating with the heater the portion of the subterranean formation; removing the first tool from the borehole; orienting a second tool having a sampling probe in the borehole so that the sampling probe is to contact a portion of the subterranean formation heated by the heater; and obtaining via the sampling probe a fluid sample from the portion of the subterranean formation heated by the heater.
摘要:
Apparatus and methods to remove impurities at a sensor in a downhole tool are disclosed. During the testing and/or sampling of formation fluid in a borehole, the downhole tool creates a transient high rate of fluid flow of the formation fluid to remove impurities at the sensor.
摘要:
Methods and apparatus to characterize stock-tank oil during fluid composition analysis are disclosed. A disclosed example method to characterize a fluid associated with an underground geological formation comprises obtaining a sample of the fluid associated with the underground geological formation, determining, in a borehole associated with the underground geological formation, a stock-tank oil type for the sample of the fluid associated with the underground geological formation, and determining a property of the fluid associated with the underground geological formation based on the stock-tank oil type.
摘要:
Apparatus and methods to monitor contamination levels in a formation fluid are disclosed. An example method involves obtaining first property data indicative of a first fluid property of a formation fluid and second property data indicative of a second fluid property of the formation fluid. A correlation between the first and second property data is generated and third data is fitted to the correlation. A fitting parameter is determined based on the third data indicative of an amount of change of the first property data relative to an amount of change of the second property data.
摘要:
Apparatus and methods to monitor contamination levels in a formation fluid arc disclosed. An example method involves obtaining first property data indicative of a first fluid property of a formation fluid and second property data indicative of a second fluid property of the formation fluid. A correlation between the first and second property data is generated and third data is fitted to the correlation. A fitting parameter is determined based on the third data indicative of an amount of change of the first property data relative to an amount of change of the second property data.
摘要:
Methods of calibrating a fluid analyzer for use in a wellbore are described. An example method of generating calibration data for a fluid analyzer for use in a downhole tool involves lowering a downhole tool including a fluid analyzer to a location in a wellbore, measuring, via the fluid analyzer, a characteristic value of a calibration fluid or a vacuum while the fluid analyzer is at the location, obtaining an expected characteristic value for the calibration fluid or the vacuum at the location, and comparing the measured characteristic value to the expected characteristic value to generate a calibration value for the fluid.