From on production in 1997 to 2002, Paleozoic Erathem carbonate-rock gas pool in Changqing gas field has built up accumulative production capacity of 39.
长庆靖边下古生界碳酸盐岩气藏自1997年投产以来，到2002年底已累计建成年产39。
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The ophiolite is composed of metamorphic peridotite, accumulative gabbro and the upper-seated basic volcanic rock series.