| Array acoustic logging on behalf of the current international advanced acoustic logging technology, which not only evaluate lithology,porosity, permeability and fluid properties, but also evaluate the extent and effectiveness of fracture development, formation of horizontal anisotropy and the mechanical properties of rock and formation to stress. In this paper, reef reservoirs using array acoustic logging, combined with other logging data, the formation of fractured identification, calulation and permeability fractured quantitative evaluation methods, and the identification and evaluation of oil and gas well logging methods.In considering the character of acoustic sonde in DSI or XMAC (Dipole shear sonic imager or Multipole array acoustic tool) and results of theroetical and experimental analysis, P-wave, S-wave and extacted by using STC (slowness-time coherence) under the constraint of stratigraphic continuity. The quality of picking up information is satisfiable from DSI or XMAC log data in many conditions. However, when there are some arrival time and frequency overlap phenomena in full waveforms gained by acoustic logs, it is very difficult to process waveforms with convertional arrival time separating methods.This article extracted pore fluid pressure formation from the sonic, density and resistivity logging data, the establishment of the stratigraphic normal compaction trend line to predict formation pressure profile of the borehole, horizontal distribution of the study area Mainland pressure. And the testing laboratory of rock mechanics parameters, combined with results of previous studies, the establishment of the calculation model for the region’s inherent strength of rock.Based on experimental data, We determine the conversion model of Rock mechanics parameters to static and dynamic, logging evaluation methods for rock mechanics parameters to calculate the rock static Poisson’s ratio, elastic modulus (Young’s modulus, shear modulus, bulk modulus) and rockthe inherent strength (compression, shear and tensile strength) of rock mechanics parameters; combination of field water fracturing data, generalized tectonic stress coefficient in the existing main stress model based on the level of elasticity, the establishment of suitablethe region’s principal horizontal stress calculation model for the quantitative calculation of this region the maximum, minimum horizontal principal stress.Carried out according to the calculation of the maximum, minimum horizontal stress data, formation shear fracture and tensile fracture pressure studies, to obtain the formation fracture pressure and collapse index, formation pressure and formation collapse pressure to calculate the critical production pressure, and wellbore stabilitywere analyzed to determine the range of "safe" drilling fluid density; based on the maximum tensile stress theory, the use of rock mechanics parameters section, calculate the factor of the rock strength and fracture toughness factor, determined according to the relationship between fracturing cracks whether longitudinalextension to achieve a high level of purpose to predict pressure cracks, provide the basic data for the whole gas field hydraulic fracturing optimization.According to the experimental results, the compressive strength of rock tensile strength of12～20times, the shear strength5～8times the experimental value is higher than the theoretical value, rock dynamic, static elastic parameters are generally linear relationship: work areaconglomerate reservoir of Young’s modulus, Poisson’s ratio and compressive strength than sandstone. According to the results, conglomerate, sandstone formation fracture pressure value with the Young’s modulus, Poisson’s ratio increases and decreases with the porosity decreases:collapse pressure increases with the porosity increase, with Young’smodulus decreases. Under the same circumstances, the fracture pressure of the conglomerate formation with Young’s modulus, porosity changes faster:value of the collapse pressure of the sandstone formation with the porosity, the Young’s modulus changes faster than the conglomerate reservoir. Lithology, pore development is a key factor to affect the formation fracturing operation. Studies have shown that pore development stratum relatively tight formations easier to fracturing or sidewall is easy to collapse; through the work area cracks fracturing height forecasts shows that the construction of pressure is greater than a certain value. Fracturing direction generally easy extension to the conglomerate reservoir fracturing height value is greater than the sandstone reservoirs value.Completed the collection and collation of the work area of the data:the full waveform of the20wells and conventional log data and the corresponding fracture test data:completion of20wells of the transverse waves, longitudinal waves, Stoneley each waveform information on ingredientsextraction, based on extraction of the longitudinal wave velocity information to strike a work area of rock elastic parameters (Young’s modulus, Poisson’s ratio), a work area wellbore formation pore-pressure prediction based on the improved method of Eaton;Determination of experimental rock mechanics to complete the work area pearl red group, pearl red formation in static and dynamic modulus conversion relationship based on experimental results:the work area to stress, the formation fracture pressure and mud weight breakdown of the fracturing height calculation method; processingexplained the work area20well logging data, and analysis of lithology, physical properties, and other factors on rock elastic parameters, inherent strength.Methods in this article have been verified in Jiulongshan oil fields, the effect is better, Jiulongshan area of reef is similar to reservoir evaluation and development of oil and gas has a strong reference. Therefore, this research not only has great theoretical significance, but also has important practical value. |
PDF Full Text Request