已发表: 01/20/2014
已发表: 01/20/2014
Middle East carbonates frequently are heterogeneous in nature, encompassing variable pore types, strong diagenetic overprints, variable wettability and fracture networks among other effects. Resistivity borehole images have long been an integral constituent to understanding their complexity and unlocking volumes. High resolution LWD resistivity images were first introduced in the 1990s, however as downhole environments became progressively more challenging, resistivity images suffered from the dynamic acquisition environment resulting in severely degraded images.
The Al Shaheen field has been developed with Extended Reach Drilling (ERD) wells, and wells of 30,000 feet are commonplace. Early LWD resistivity image data suffered from excessive stick and slip, with approximately half of the wellbore suffering from poor quality image data, degrading with depth. The outer portion of the wellbore is prohibitive to impossible to access via conventional drill pipe conveyed tools, resulting in an absolute requirement for high quality LWD resistivity images.
The new methodology redefines the acquisition and processing methodology, resulting in images unaffected by stick slip with a 100% success rate in the most challenging of ERD environments.
This paper illustrates the improvements in logging while drilling images (LWD) and subsequent fracture network characterization as a result of implementing a new image acquisition strategy and processing algorithm. The paper explores the close collaboration necessary to drive the innovation to dramatically enhance existing technology, and demonstrates the results with comparisons of the LWD images using the old and new methodologies.