花状构造及其对油气勘探的意义

花状构造是发育于走滑-拉分盆地内的一种扭动构造,其基本特征是近于直立的基底扭断裂向上分叉撒开。花状构造大致可以构成三种基本油气圈闭类型,即背形花蕊、屋脊和朵下封堵。由于扭断裂作用,有可能改善脆性基岩的储集性质,所以花状构造一般具有较好的储集条件。此外,花状构造对油气的运移和聚集有它自身的规律。因此,花状构造油气田的开发有其独特性。我国东部西部均发育了一系列走滑—拉分性质的中新生代盆地,其中有可能发育一些花状构造。百色盆地的勘探实践已经发现了正花状构造的存在,在西西盆地还发现一个负花状构造。

Flower structure and its significance to hydrocarbon exploration.

Flower structure is a torsional structure which occurs in strike-slip basins or pull-apart basins; on the whole, it is a vertical basement torsion fault system that branches upwardly. The flower structure mainly results in three kinds of oil trap, namely, inside anticlinal top, roof and downward sealing. The torsional faulting may improve the reservoiring of brittle base rock, so that flower structure usually has good reservoir condition. Oil and gas accumulate and migrate in a special way in the flower structure; therefore, the development of such oil and gas resources should follow the special regularity. Strike-slip or pull-apart sedimentary basins occur in Mesozoic or Cenozoic erathem in East or Mid China, and some flower structures may be discovered in these basins. Positive flower structure has been found in the Baise basin, and negative flower structure in the Jiuxi basin.