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Multi-lateral well drilling and completion technology

Two breakthroughs for key technology have emerged. - the establishment of a downhole tee at branch connection points and a branch string lateral re-entry. A DF-1 patent technology has been successfully developed to form two tool series at 9 5/8″ and 7″, and applied in TAML 5 level well completion. Over 50 multi-lateral wells covering various types can now be run each year.

    GWDC drilled the first multilayer lateral well in China containing 2 TAML 4 lateral branches and 5 or 6 fish bone branches in each lateral branch, achieving 12 fish bone branches and a total drilling footage of 6655m, a reservoir footage of 4370m, an initial daily oil output of 60t and a stable oil output of 30t. The production in this well is 6-10 times of that in adjacent wells in the same block. GWDC also completed one fishbone horizontal well in a buried-hill high pour point oil reservoir having the most branches and the longest horizontal footage in China. This well has a total of 20 fishbone branches, a total footage of 7587m, a total reservoir footage of 4567m, a total horizontal length of 4344m, a main horizontal length of 1000m, and an initial daily output of 52 tons.

    In total, up to 110 multi-lateral wells have been completed, which accounts for over 80% in China. Amongst these, several key technologies with respect to multi-lateral wells were developed in China for the first time. The average output of these wells is 4-5 times as that of adjacent wells, giving a significant production increasing effectiveness.