珠江口盆地番禺4洼断块圈闭勘探成效及影响因素

EXPLORATION EFFICIENCY IN FAULT-SEALED TRAPS AND INFLUENCE FACTORS:A CASE FROM PY4 SAG OF PEARL RIVER MOUTH BASIN

通过对珠江口盆地番禺4洼主要油层进行储量统计发现,断层控制了80%的已发现储量,断层圈闭勘探中断层封堵风险相对较小。针对番禺4洼断层封堵影响因素的实际情况,提出了泥岩发育结构的概念,通过对主要油层的泥岩发育结构的统计发现,当泥岩发育结构中厚度>2m的泥岩含量占60%以上时,断层涂抹封堵效果较为理想;而当厚度<2m的泥岩含量超过40%时,地层多表现为砂泥岩薄互层,对泥岩涂抹封堵不起建设性作用。综合认为泥岩发育结构是影响番禺4洼地区断层封堵效果的关键因素。

Statistics of reserves in the main oil layers of PY4 Sag suggest that the fault-controlled reserve is nearly up to 80% of the total found until 2012.It means that the exploration of fault traps in the PY4 Sag is low in risk.In order to better study the control factors of a fault sealed reservoir of the PY4 Sag,we proposed in this paper a new concept of Composition of Shalestone Development,CSD in brief.According to the research of the CSD for the main oil layers of the PY4 Sag,it is found that when the content of shale stones thicker than 2m is above 60%,it is excellently sealed;otherwise,when the content of shale stone thinner than 2mis above 40%,the sealing is very poor.Based on our study,the CSD is the key factor controlling fault sealing in the PY4 Sag.