Application of Direct-Push Storage Logging Technology in the Northwest Oilfield

Conventional wireline logging cannot be carried out safely in the Northwest Oilfield due to lost circulation or overflow which often occurs in carbonate reservoirs. Because of well depth and high hydrogen sulfide content, as well as the small space between casing and drilling string in some inclined or horizontal wells, it is impossible to carry out wireline logging. To solve the difficulties in acquiring full logging data in complex environments of Northwest Oilfield, a new direct-push storage logging technology free of cables and docking was introduced. Further, introductions of the components, main technical indexes of this logging system were made, and the its technological characteristics were analyzed. Practical applications in Shunbei, Tahe and some peripheral blocks confirmed its higher safety and reliability, and it could shorten the time of occupying wellhead for logging and greatly improve completion efficiency. Besides, this new technology allows one to acquire full logging data while ensuring the safe service of downhole instruments and wellhead safety under complex well conditions or in wells with risks in well control. The acquisition rate of logging data in the target layers was significantly improved, for example, that of the Shunbei area was improved from 31.25% to 90.91%. The research results showed that the direct-push storage logging technology could acquire accurate and reliable data, and could meet the needs of reservoir evaluation, making it worthy of popularization and application.