Application of rotary geosteering drilling in deep and thin reservoirs of Tarim Basin, NW China

A Numerical 1.5D Method for the Rapid Simulation of Geophysical Resistivity Measurements

“…The large apparent resistivity values observed in Figures 8 and 9 form the so-called horns. They are a typical artifact that appears due to the employed post-processing method [10,16]. Moreover, they do not affect significantly to the interpretation of the results.…”

“…We categorize these resistivity prospection methods according to their acquisition location as (a) on surface, such as the ones obtained using controlled sources electromagnetics (CSEM) [1][2][3] and magnetotelluric [4], and (b) in the borehole, such as the ones obtained using logging-while-drilling (LWD) devices. LWD is a technology that conveys borehole logging tools (e.g., gamma ray, resistivity, density, and sonic) downhole, record measurements, and transmit them to the subsurface for real time interpretation while the hole is being drilled [5][6][7][8][9][10][11][12]. These tools provide two pieces of information: (a) real-time data, which is processed on the field while drilling, and (b) data that is stored in the device to process after pulling it out from the hole.…”

“…These tools provide two pieces of information: (a) real-time data, which is processed on the field while drilling, and (b) data that is stored in the device to process after pulling it out from the hole. We use real-time data to evaluate the formation for geosteering, which is the act of adjusting inclination and azimuth angles of the borehole to reach a geological target [5][6][7][8][9][10][11].…”

“…They were commercially used for formation evaluation, especially in high-angle wells. Nowadays, LWD devices are used both for reservoir characterization [6][7][8] and geosteering applications [9][10][11]. Modern borehole resistivity instruments can measure all nine couplings of the magnetic field, namely xx, xy, xz, yx, yy, yz, zx, zy and zz couplings (the first letter indicates the orientation of the transmitter and the second one indicates the receiver orientation) [13,14].…”

Borehole resistivity simulations of oil-water transition zones with a 1.5D numerical solver

“…We categorize existing resistivity measurements as: (1) on surface, such as those obtained using controlled source electromagnetic (CSEM) [1][2][3][4][5] and Magnetotellurics (MT) [6,7]; and (2) borehole resistivity measurements, for example, those acquired using logging-while-drilling (LWD) devices [8][9][10][11][12][13][14][15][16][17][18][19]. LWD devices are useful both for reservoir characterization [20][21][22] and geosteering purposes [23,24], which is the act of adjusting the tool direction to travel through a specific zone.…”