Logging while drilling and geosteering technology

(Shumilov A.V. Shao CaiRui Cao XianJun Zhang FuMing )

This paper introduces the development of LWD and geosteering in China, and gives the key technologies of the geosteering software developed by China university of petroleum: the well site LWD data real-time receiving, interpretation, 2D and 3D visualization and formation model updating. At last, one and validity of the independent property rights software.......

  • 2014  № 5, pp. 68-75

Bayesian AVAZ inversion with model constraint for fracture weaknesses

(Zhaoyun Zong Xingyao Yin Guochen Wu Laptev A.P. )

Azimuthal elastic inversion (AVO/AVA analysis) has a large potential for fracture characterization in the productive fractured strata of the shale gas and oil reservoirs. «Looseness» of the geological medium, caused by fracturing, including normal and tangential looseness, in accordance with «theory of surfaces with a linear slip» is a bridge between the seismic data and fracture characteristics. However, stability of the azimuthal elastic inversion methods for assessment of the anisotropy parameters and/or fracturing parameters using seismic data is debatable. This study explores an amplitude variation with incident angle and azimuth (AVAZ) inversion approach with model constraint for fracture weaknesses in Bayesian inversion scheme. Based on perturbation theory and stable phase approximation, the fracture medium can be considered as the superimposition of background medium and perturbation medium, and then the seismic scattering coefficient of fracture media can be derived. This equation establishes the relationship between seismic data and fracture weakness together with elastic parameters like P-wave and S-wave moduli and weaknesses. With this equation, an inversion approach in Bayesian scheme is proposed. This method implements the estimation of P-wave modulus, S-wave modulus, density, normal weakness and tangential weakness simultaneously. And the constraint from initial model enhances the stability of this method. In this approach, Gaussian and Cauchy distributions are explored for the likelihood and a priori probability distributions, respectively.......

  • 2014  № 5, pp. 83-87

Reflections on the structure of a new book on the subject «Gravitational exploration» for students of universities

(Kostitsyn V.I. Dolgal A.S. )

Offers to make the course “Gravitational Exploration” better on teaching students of institution of higher education are presented. These proposals can form the core of a new textbook. It is suggest including in the book latest advances in the equipment and in the method of gravimetrical surveys, new approaches in processing and interpretation of observed gravity data, the experience at solving actual geological problems. It is worthwhile to refuse from the statement of obsolete technologies of field and cameral works.......

  • 2014  № 5, pp. 88-93

Magnetotelluric studies of geothermal resources

(Pushkarev P.Yu. Khmelevskoy V.K. Boychenko D.A. Golubtsova N.S. Ivanova K.A. Slepykh K.S. Khutorskoy M.D. )

The paper describes magnetotelluric investigations of geothermal resources, which we subdivide into hydrothermal and petrothermal. Hydrothermal resources are typical for active tectonic zones and are exploited for a long time, while magnetotellurics is widely used for their exploration. We constructed a typical resistivity model of a hydrothermal zone and, using synthetic data, evaluated the possibilities of data interpretation methods. Petrothermal resources are related with heat content of crustal rocks and their thermal potential is hundred times bigger than that of hydrothermal resources. However, for their extraction deep drilling is required, especially in stable tectonic continental regions. We consider the prospects of magnetotelluric for regional prognosis of petrothermal resources, as well as for detailed exploration and monitoring of deep heated reservoirs.......

  • 2014  № 4, pp. 2-7