سؤال علمي (2)

[Ahmed Al-Khaledi]

How we could calculate the formation dip in degree from a gamma ray or resistivity curve, log

يالله يا أبطال عطونا اللإجابة

[Don_Geo]

يالخالدي جايتك الاجابه انشالله ................ لي عوده مع الاجابه .............

[Don_Geo]

الاجابه :

Gamma Ray or Resistivity: Measured Depth Modeling
One method commercially available within the industry models offset vertical resistivity and gamma ray logs to mimic predicted response seen in the measured depth log. The logs are then plotted along the trajectory axis (measured depth) and compared with the actual measured depth log. This technique, while solving the spatial relationship problem encountered in the Visual Interpretation method does not solve any of the correlation problems associated with the previous method.

Measured Depth Log is stretched out: Most horizontal wells are drilled nearly parallel to formation dip. Trying to determine the position of a wellbore within the vertical stratigraphic section from patterns seen in a measured depth log recorded on a near horizontal plane can be very challenging if not impossible. A measured depth MWD log will typically see less than four feet of stratigraphic section in one hundred feet of drilling, making it extremely difficult for the mind to receive the visual queues necessary to correlate with nearby vertical wells.

Faults are a problem: Correlation becomes even more difficult if there is a discontinuity in the data such as a fault. A fault will place the wellbore either up or down in the stratigraphic section.

Modeling vertical logs to mimic the measured depth logs can be complex. Modeling a vertical log to mimic the measured depth log in a faulted area can be quite challenging. Even in areas with relatively simple geology, resistivity logs must be highly modeled to depict bed boundaries. Blending of bed signatures can make modeling very complex when beds are very thin or highly heterogeneous in character. Even if the modeling is perfect, resistivity is a poor correlation tool for placing a wellbore within the stratigraphic section, since resistivity can vary radically within the same stratigraphic interval.

[Ahmed Al-Khaledi]

كلام كبير حبيب قلبي don_geo وإجابتك صح. بس في quick calculation method عشان نحسب ميل الطبقات الصخريه. هذا الي انا ابيه؟

[Geo_Q8]

i can give you the answer by example

let assume Formation X top on the offset well @ 1000 ft (TVD) and in the current well 1020 ft ( TVD)

and the vertical section ( distance between formation top in the offset well and formation top in the current ) = 200

so, formation dip = TAN inverse delta (1020-1000)/ vertical section 200

0.1=

TAN Inverse 0.1 = 5.71 degree

[Ahmed Al-Khaledi]

ممتاز يا بو عبدالعزيز ....ما شاء الله عليك. عيني عليك باردة. كفيت ووفيت. إجابه رائعه

[Don_Geo]

عاد هذا شغل الجيوفيزيائيين ، احنه الارقام تعور راسنا ، بس نعرف نشرح ونفهم الشي بدون ارقام ...

لكن اذا صار فيها حسابات وجمع وطرح اهني انا ابدي اصدع ........

[Ahmed Al-Khaledi]

للتصحيح هذا شغل البتروفيزيائيين

[Don_Geo]

شكرا على التصحيح ...........

ومنكم نتعلم

[عهد الاشواق]

عاد انا السؤال مافهمته عشان افهم الإجابه والله اطالع واضحك الحمد لله ان برابعه ماعندنه جيولوجيه مع اني احب المادة بس دراستها كلش مو شي يبيله نصم الكتاب وندش الإمتحان

[ahmadye]

استفسار ممكن......
المعروف في الخليج عن قلة المياه الجوفيه وسؤالي للاخوة الجيولوجيين في حال تم حقن الاراضي بمياه تم تحليتها هل هناك امل او استفاده من المياه التي تم حقنها في الارض وتزيد من كميتها في باطن الارض