Method for obtaining fault rock displacement pressure based on rock debris

Abstract

The invention discloses a method for obtaining fault rock displacement pressure based on rock debris. The method comprises the following steps: (1) performing rock debris depth correction; (2) calculating the surrounding rock displacement pressure according to the correction result of the rock debris depth in the step (1); (3) calculating fault rock displacement pressure, enabling fault rock to be equivalent to a horizontal stratum at a certain depth underground, and recording the thickness of a small layer of a surrounding rock i outside a fault zone as delta Zi; calculating according to a formula III to obtain fault rock displacement pressure; wherein Pdf is equal to 0.00191n(H<fault>*(rho r - rho w)*cos theta / rho<r>* Sigma(Vshi*Delta Zi / D)*100%)-0.0052 (formula III), and in the formula III, Pdf is fault rock beat replacement pressure in the unit of MPa; rho r is rock density in the unit of g / cm<3>; rho w is underground water density in the unit of g / cm<3>; theta is a fault inclination angle in the unit of degree, and H<fault> is a fault burial depth in the unit of m; Vshi is the argillaceous content of the small layer of the surrounding rock i outside the fault zone, delta Zi is the thickness of the small layer of the surrounding rock i outside the fault zone, and D is the vertical fault distance. According to the method, measured rock debris data are analyzed, and the data are easy to obtain; related research is carried out on the basis of the measured rock debris data, the result accuracy is high, and the fault plugging research cost is greatly reduced.

Description

technical field [0001] The invention relates to a method for obtaining displacement pressure of fault rocks based on cuttings, and belongs to the field of oil field exploration and development. Background technique [0002] Fault rock displacement pressure is the key data for judging the sealing performance of faults. The existing technology is generally based on direct measurement of fault rock cores or indirect derivation of surrounding rock cores. No matter which method is used, the calibration of core data is inseparable. However, in many oil fields, especially offshore or deepwater oil fields, the cost of coring is high, and cores are very scarce, which limits the research on fault sealing. Compared with conventional techniques, this technique infers the displacement pressure of fault rocks based on cuttings analysis and test data, which not only broadens the research methods of fault sealing, but also reduces the research cost of fault sealing. Contents of the inve...

AI Technical Summary

Problems solved by technology

However, in many oil fields, especially offshore or deepwater oil fields, the cost of coring is high, and cores are very scarce, which limits the research on fault sealing

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