Basic Petroleum Geology - Terminlogoy

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    Basic Petroleum Geology - Terminlogoy

    مُساهمة من طرف mhmoudkhlifa في 2007-10-29, 2:39 pm

    احببت من خلال هذا الموضوع أن أضع بعض المصطلحات العلميه المستخدمه في جيولوجيا البترول ، والتي هي مفيده جدا لكل من يريد فهم جيولوجيا البترول


    The intentional directional control of a well based on the results of downhole geological logging measurements rather than three-dimensional targets in space, usually to keep a directional wellbore within a pay zone. In mature areas, geosteering may be used to keep a wellbore in a particular section of a reservoir to minimize gas or water breakthrough and maximize economic production from the well.

    directional drilling

    The intentional deviation of a wellbore from the path it would naturally take. This is accomplished through the use of whipstocks, bottomhole assembly (BHA) configurations, instruments to measure the path of the wellbore in three-dimensional space, data links to communicate measurements taken downhole to the surface, mud motors and special BHA components and drill bits. The directional driller also exploits drilling parameters such as weight on bit and rotary speed to deflect the bit away from the axis of the existing wellbore. In some cases, such as drilling steeply dipping formations or unpredictable deviation in conventional drilling operations, directional-drilling techniques may be employed to ensure that the hole is drilled vertically. While many techniques can accomplish this, the general concept is simple: point the bit in the direction that one wants to drill. The most common way is through the use of a bend near the bit in a downhole steerable mud motor. The bend points the bit in a direction different from the axis of the wellbore when the entire drillstring is not rotating. By pumping mud through the mud motor, the bit turns while the drillstring does not rotate, allowing the bit to drill in the direction it points. When a particular wellbore direction is achieved, that direction may be maintained by rotating the entire drillstring (including the bent section) so that the bit does not drill in a single direction off the wellbore axis, but instead sweeps around and its net direction coincides with the existing wellbore. Rotary steerable tools allow steering while rotating, usually with higher rates of penetration and ultimately smoother boreholes.


    The angle between the vertical projection of a line of interest onto a horizontal surface and true north or magnetic north measured in a horizontal plane, typically measured clockwise from north.

    Alternate Form: azimuthal

    See: attitude, dip, strike, trend


    The compass direction of a directional survey or of the wellbore as planned or measured by a directional survey. The azimuth is usually specified in degrees with respect to the geographic or magnetic north pole.

    See: directional drilling, inclination, survey

    [Reservoir Characterization]

    The angle that characterizes a direction or vector relative to a reference direction (usually True North) on a horizontal plane. The azimuth is usually quoted in degrees from 0 to 359.

    horizontal drilling

    A subset of the more general term "directional drilling," used where the departure of the wellbore from vertical exceeds about 80 degrees. Note that some horizontal wells are designed such that after reaching true 90-degree horizontal, the wellbore may actually start drilling upward. In such cases, the angle past 90 degrees is continued, as in 95 degrees, rather than reporting it as deviation from vertical, which would then be 85 degrees. Because a horizontal well typically penetrates a greater length of the reservoir, it can offer significant production improvement over a vertical well.

    directional well

    A wellbore that requires the use of special tools or techniques to ensure that the wellbore path hits a particular subsurface target, typically located away from (as opposed to directly under) the surface location of the well.

    slant rig

    Angled drill rig in a field operated by Petro-Canada. This special rig enables wells in this field to be drilled at a 45° angle so they can make the turn to horizontal by a target depth of 400 ft [122 m].

    1. [Formation Evaluation]
    Related to any aspect of logging that employs an electrical cable to lower tools into the borehole and to transmit data. Wireline logging is distinct from measurements-while-drilling (MWD) and mud logging.

    2. [Well Workover and Intervention]
    A general term used to describe well-intervention operations conducted using single-strand or multistrand wire or cable for intervention in oil or gas wells. Although applied inconsistently, the term commonly is used in association with electric logging and cables incorporating electrical conductors. Similarly, the term slickline is commonly used to differentiate operations performed with single-strand wire or braided lines.


    [Well testing]

    Test taken with a wireline formation tester. The wireline formation pressure measurement is acquired by inserting a probe into the borehole wall and performing a minidrawdown and buildup by withdrawing a small amount of formation fluid and then waiting for the pressure to build up to the formation pore pressure. This measurement can provide formation pressures along the borehole, thereby giving a measure of pressure with depth or along a horizontal borehole. The trend in formation pressure with depth provides a measure of the formation-fluid density, and a change in this trend may indicate a fluid contact. Abrupt changes in formation pressure measurements with depth indicate differential pressure depletion and demonstrate barriers to vertical flow. Lateral variation in formation pressure measurements along a horizontal well or in multiple vertical wells indicate reservoir heterogeneity.

    wireline log

    1. [Drilling]

    A continuous measurement of formation properties with electrically powered instruments to infer properties and make decisions about drilling and production operations. The record of the measurements, typically a long strip of paper, is also called a log. Measurements include electrical properties (resistivity and conductivity at various frequencies), sonic properties, active and passive nuclear measurements, dimensional measurements of the wellbore, formation fluid sampling, formation pressure measurement, wireline-conveyed sidewall coring tools, and others. In wireline measurements, the logging tool (or sonde) is lowered into the open wellbore on a multiple conductor, contra-helically armored wireline. Once lowered to the bottom of the interval of interest, the measurements are taken on the way out of the wellbore. This is done in an attempt to maintain tension on the cable (which stretches) as constant as possible for depth correlation purposes. (The exception to this practice is in certain hostile environments in which the tool electronics might not survive the temperatures on bottom for the amount of time it takes to lower the tool and then record measurements while pulling the tool up the hole. In this case, "down log" measurements might actually be conducted on the way into the well, and repeated on the way out if possible.) Most wireline measurements are recorded continuously even though the sonde is moving. Certain fluid sampling and pressure-measuring tools require that the sonde be stopped, increasing the chance that the sonde or the cable might become stuck. LWD tools take measurements in much the same way as wireline-logging tools, except that the measurements are taken by a self-contained tool near the bottom of the bottomhole assembly and are recorded downward (as the well is deepened) rather than upward from the bottom of the hole (as wireline logs are recorded).

    logging while drilling (LWD)

    1. [Drilling]

    The measurement of formation properties during the excavation of the hole, or shortly thereafter, through the use of tools integrated into the bottomhole assembly. LWD, while sometimes risky and expensive, has the advantage of measuring properties of a formation before drilling fluids invade deeply. Further, many wellbores prove to be difficult or even impossible to measure with conventional wireline tools, especially highly deviated wells. In these situations, the LWD measurement ensures that some measurement of the subsurface is captured in the event that
    wireline operations are not possible.[/size]

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    رد: Basic Petroleum Geology - Terminlogoy

    مُساهمة من طرف megoscientist في 2007-11-14, 9:15 pm

    very good information
    i donnow how no one reply this topic but again nice work

      الوقت/التاريخ الآن هو 2018-06-23, 8:53 pm