准噶尔盆地西北缘油气藏保存及破坏定量研究

QUANTITATIVE RESEARCH ON PRESERVATION AND DESTRUCTION OF HYDROCARBON ACCUMULATION IN THE NORTHWEST EDGE OF JUNGGAR BASIN

准噶尔盆地西北缘构造运动复杂 ,其油气藏破坏因素多 ,油气显示也呈多样化形式 (稠油、油砂、沥青 )。该地区油气藏虽然破坏量很大 ,但同时也是盆地油气的最富集区。对油气藏破坏因素的分析表明 ,西北缘的油气藏破坏类型以断裂活动、油藏抬升和褶皱变动为主。多种估 (计 )算方法 (盆地模拟法、区带地质分析法、地质锚链法 ) ,分别定量地估 (计 )算了西北缘油气原始聚集量、保存量、破坏量、残留量和散失量。结果表明 ,西北缘油气总散失量占原始总聚集量的 72 1%～ 78 1% ,其散失量在燕山期最大 ,印支期次之 ,喜山期最小 ,这与西北缘油源丰富、单斜地质构造、多期成藏。

Despite the fact that it is complicated for tectonic movement in the northwest edge of Junggar Basin and there are many factors for destruction of hydrocarbon accumulation and indication such as dense oil,oil sand and bitumen,it is still the most accumulated area for hydrocarbon.The analysis on destructive factors of oil and gas pools shows that there are three primary destructive types of factors,including rupture activety,up-lifting of oil pool and fold alteration.Using basin modeling,FASPUM and geoanchored methods,the amounts of initial hydrocarbon accumulation,preservation,destruction,residue and loss were calculated respectively.The whole quantity of hydrocarbon loss accounts for 72.1% to 78.1% of initial hydrocarbon accumulation in the northwest edge of Junngar Basis.The biggest loss was produced in Mid-Late Mesozoic,and the bigger loss was in Late Paleozoic,and the smallest loss was in Cenozoic.The loss distribution are related to rich source,single-slope structure,hydrocarbon multi-period accumulation,long multi-period loss,and destructive multifactors.