The development of unconventional oil and gas resources is critically dependent on accurate geosteering of horizontal wells.A new type of LWD Azimuthal Laterolog Resistivity logging tool has been introduced that is specifically designed for geosteering and formation evaluation in complex carbonates, shale-gas, shale-oil, and coal-bed methane formations.Laterolog types of tools are capable of accurate measurement over a wide range of resistivity from 0.2-20,000 ohm.meters, enabling hydrocarbon saturation calculation even in tight carbonate formations.In contrast, conventional wave-propagation types are limited to less than 200 ohm.meter formations.The first tests in China were in Talimu Oilfield where the new tool was able to reproduce logs from a wireline Dual-Laterolog in resistivities ranging from 1,000 to 40,000 ohm.meters.Tests have also been run in Tuha, Sulige, and Changqing (Gansu) oilfields.The new tool is able to detect approach to a distant bed-boundary of contrasting resistivity, either higher or lower.Conventional wave-propagation tools respond mainly to a nearby conductive anomaly, which limits their application in geosteering shale-oil wells such as the Bakken Formation in the USA where the target formation is of lower resistivity than those on upper or lower boundaries.Many carbonate formations, and most coal seams, produce from natural fractures.The new tool has thin-bed resolution of 0.15 meters, enabling it to image the more productive zones for real-time production analysis while drilling, with significant cost-savings.A description of the tool design theory, unique real-time geosteering display, and log presentation software is presented.Some results from two years of operations in North America will be discussed.The authors also show some examples of drilling test results along with case studies in several oilfields in China.