Downhole densitometer
    71.
    发明授权

    公开(公告)号:US06543281B2

    公开(公告)日:2003-04-08

    申请号:US10134258

    申请日:2002-04-29

    IPC分类号: E21E4400

    摘要: A measurement device is provided that determines fluid properties from vibration frequencies of a sample cavity and a reference cavity. In one embodiment, the measurement device includes a sample flow tube, a reference flow tube, vibration sources and detectors mounted on the tubes, and a measurement module. The sample flow tube receives a flow of sample fluid for characterization. The reference flow tube is filled with a reference fluid having well-characterized properties. The measurement module employs the vibration sources to generate vibrations in both tubes. The measurement module combines the signals from the vibration detectors on the tubes to determine properties of the sample fluid, such as density, viscosity, compressibility, water fraction, and bubble size. The measurement module may further detect certain flow patterns such as slug flow, for example. To measure the sample fluid density, the measurement module determines the difference between resonance frequencies of the sample flow tube and the reference flow tube. The density can then be calculated according to a formula. Other fluid properties may be determined from the sample tube's resonance peak amplitude, peak width and/or peak shape. Variation of the density measurements may be used to detect and characterize multiple phase fluid flow. The use of a reference tube in the disclosed measurement device is expected to greatly enhance the accuracy and reliability of the measurement device over a range of temperatures, pressures, and shock accelerations such as those that may be found downhole in a well.

    Downhole densitometer
    72.
    发明授权

    公开(公告)号:US06378364B1

    公开(公告)日:2002-04-30

    申请号:US09482793

    申请日:2000-01-13

    IPC分类号: E21B4400

    摘要: A measurement device is provided that determines fluid properties from vibration frequencies of a sample cavity and a reference cavity. In one embodiment, the measurement device includes a sample flow tube, a reference flow tube, vibration sources and detectors mounted on the tubes, and a measurement module. The sample flow tube receives a flow of sample fluid for characterization. The reference flow tube is filled with a reference fluid having well-characterized properties. The measurement module employs the vibration sources to generate vibrations in both tubes. The measurement module combines the signals from the vibration detectors on the tubes to determine properties of the sample fluid, such as density, viscosity, compressibility, water fraction, and bubble size. The measurement module may further detect certain flow patterns such as slug flow, for example. To measure the sample fluid density, the measurement module determines the difference between resonance frequencies of the sample flow tube and the reference flow tube. The density can then be calculated according to a formula. Other fluid properties may be determined from the sample tube's resonance peak amplitude, peak width and/or peak shape. Variation of the density measurements may be used to detect and characterize multiple phase fluid flow. The use of a reference tube in the disclosed measurement device is expected to greatly enhance the accuracy and reliability of the measurement device over a range of temperatures, pressures, and shock accelerations such as those that may be found downhole in a well.

    Apparatus and method for analyzing a retrieving formation fluid
utilizing acoustic measurements
    73.
    发明授权
    Apparatus and method for analyzing a retrieving formation fluid utilizing acoustic measurements 失效
    使用声学测量分析回收地层流体的装置和方法

    公开(公告)号:US5741962A

    公开(公告)日:1998-04-21

    申请号:US628408

    申请日:1996-04-05

    摘要: This invention provides a closed-loop system for in situ testing of formation fluid conditions and for selectively collecting substantially mud filtrate free formation fluid samples at original formation conditions. The system contains an elongated member having a probe that is sealingly placed against the wellbore formation to withdraw formation fluids. A surface controlled pump controls the flow of a fluid from the formation into a flowline placed in the elongated member. A pressure sensor provides downhole hydrostatic pressure and an acoustic density cell provides the speed of sound in the fluid, acoustic impedance of the fluid and acoustic absorption coefficient of the fluid in the flowline. The system determines the density and compressibility of the formation fluid in the flowline from the speed of sound in the fluid and acoustic impedance of the fluid. The formation of the bubbles are identified or detected from the acoustic absorption coefficient of the fluid in the flowline. The system controls the movement of fluid into the flowline to selectively collect the formation fluid samples that are substantially free from any mud filtrates while maintaining the fluid pressure above the bubble point pressure of the formation fluid. This invention provides a method for retrieving and collecting formation fluids from a zone of interest in a wellbore at the original formation conditions.

    摘要翻译: 本发明提供了一种闭环系统,用于对地层流体条件进行原位测试,并在原始形成条件下选择性地基本上收集泥浆无滤液地层流体样品。 该系统包含细长构件,其具有密封地抵靠井筒地层放置以取出地层流体的探针。 表面控制的泵控制流体从地层流入放置在细长构件中的流线。 压力传感器提供井下静水压力,声学密度单元提供流体中的声速,流体的声阻抗和流线中流体的声吸收系数。 该系统从流体中的声速和流体的声阻抗来确定流线中的地层流体的密度和压缩性。 根据流线中的流体的声吸收系数识别或检测气泡的形成。 该系统控制流体流入流线以选择性地收集基本上没有任何泥浆滤液的地层流体样品,同时将流体压力保持在地层流体的泡点压力以上。 本发明提供了一种用于在原始形成条件下从井眼中的感兴趣区域中回收和收集地层流体的方法。

    Wireline formation tester supercharge correction method
    74.
    发明授权
    Wireline formation tester supercharge correction method 失效
    电线形成测试仪增压校正方法

    公开(公告)号:US5644076A

    公开(公告)日:1997-07-01

    申请号:US614617

    申请日:1996-03-14

    IPC分类号: E21B49/00 E21B49/10 E21B47/00

    CPC分类号: E21B49/10 E21B49/008

    摘要: An improved formation testing method increases the accuracy of in-situ formation pressure measurements by characterizing the mudcake properties. Specifically, after a formation tester is lowered to a desired depth within a wellbore, a pad is extended to gently abut and seal against the mudcake without disturbing the mudcake. When pressed against the mudcake, the pad experiences momentarily higher pressures, which are measured by a probe housed by the pad. These pressures may be enhanced by briefly rejecting fluids through the probe, so as to avoid disturbing the mudcake. The probe continues to measure pressure, which eventually decreases relative to hydrostatic pressure in the wellbore, due to the flow of high-pressure wellbore fluids through the mudcake. Since the rate of fluid flow outward into the formation is governed by the permeability of the mudcake, measuring the rate of pressure decline during this initial period provides useful data to more accurately estimate properties such as formation compressibility. Additionally, indicia of the mudcake properties themselves may be generated. After the initial mudcake tests, the formation tester may be used to perform drawdown and/or buildup tests, by a process of withdrawing or injection fluids into the formation through the mudcake.

    摘要翻译: 改进的地层测试方法通过表征泥浆性质来提高原位地层压力测量的准确度。 具体地说,在将地层测试仪降低到井眼内所需的深度之后,将垫延伸以轻轻地抵靠并密封在泥饼上,而不会干扰泥饼。 当压在泥饼上时,垫经历瞬间更高的压力,这是通过由垫容纳的探针来测量的。 这些压力可以通过简单地通过探针排出流体来增强,以避免干扰泥饼。 由于高压井眼流体通过泥饼的流动,探头继续测量压力,该压力最终相对于井筒中的静水压力而降低。 由于流入地层的流体流速由泥饼的渗透率决定,因此在初始阶段测量压力下降速率提供了更为准确的估计地层压缩性能的数据。 此外,可能产生泥饼性质本身的标记。 在初始泥饼测试之后,地层测试仪可以用于通过将泥浆从地层中抽出或注入流体的过程进行抽水和/或堆积测试。

    Wireline formation testing for low permeability formations utilizing
pressure transients
    75.
    发明授权
    Wireline formation testing for low permeability formations utilizing pressure transients 失效
    使用压力瞬变的低渗透地层的有线地层测试

    公开(公告)号:US5602334A

    公开(公告)日:1997-02-11

    申请号:US261512

    申请日:1994-06-17

    IPC分类号: E21B49/00 E21B49/10

    CPC分类号: E21B49/10 E21B49/008

    摘要: An improved formation testing method for measuring initial sandface pressure and formation permeability in tight zone formations exhibiting formation permeabilities on the order of 1.0-0.001 millidarcies based on pressure transients which occur shortly after the tester enters its pressure buildup cycle and substantially before reaching final buildup pressure. The method makes an estimate of formation permeability based on fluid decompression transients which occur in the formation tester flowlines which occur shortly after the tester begins its buildup cycle. The method further estimates initial sandface pressure based on the change in pressure over time shortly after beginning the buildup phase. The method of the present invention thereby permits accurate estimates of formation permeability and initial sandface pressure to be made relatively early in the buildup cycle, thus substantially reducing the time required to make the pressure and permeability measurements.

    摘要翻译: 一种改进的地层测试方法,用于测量紧密区域地层中初始砂面压力和地层渗透率,其基于在试验机进入其压力累积周期后并且基本上达到最终堆积压力之前不久发生的压力瞬变,其表现出大约1.0-0.001毫升的地层渗透率 。 该方法基于在测试仪开始累积周期后不久发生的地层测试仪流线中基于流体减压瞬变的方法估计地层渗透率。 该方法进一步基于在开始积聚阶段后不久的压力随时间的变化来估计初始砂面压力。 因此,本发明的方法允许在堆积循环中相对较早地进行地层渗透性和初始砂面压力的准确估计,从而大大减少了进行压力和渗透率测量所需的时间。