桂中坳陷泥盆系儲層特征及控制因素分析

桂中坳陷泥盆系儲層特征及控制因素分析

王劍

(中國石油新疆油田公司實驗檢測研究院，新疆克拉瑪依 834000)

摘要：桂中坳陷泥盆系具獨特的“臺—盆—丘—槽”沉積體系，沉積儲層復雜，目前泥盆系儲層研究相對較少。針對此問題，以露頭剖面觀測資料、室內巖礦鑒定、掃描電鏡等分析資料為基礎，研究了桂中坳陷泥盆系儲層發育特征及其控制因素。研究表明桂中坳陷泥盆系儲層巖石類型主要有石英砂巖、礁灰巖、生屑灰巖和白云巖。主要的儲集空間類型為原生剩余粒間孔、生物格架孔，以及次生溶孔和白云石晶間孔。研究區下泥盆統石英砂巖的物性相對較好，為裂縫—孔隙型儲層；中、上泥盆統碳酸鹽巖儲層物性總體較差，為低孔低滲型儲層，受白云化作用影響可形成物性較好儲層。影響儲層發育的主要因素為沉積相帶及后期的成巖作用，包括白云化作用和溶蝕作用。桂中坳陷北部及東北部的斜坡帶為有利儲層發育區。

關鍵詞：桂中坳陷；泥盆系；孔隙類型；儲層物性；控制因素

中圖分類號：TE122

基金項目：中國石油化工股份有限公司項目(N0801058)資助。

作者簡介：第一王劍(1984年生)，男，碩士，工程師，2011年畢業于中國石油大學(華東)，現從事沉積方面科研工作。郵箱：wangjian_2605@126.com。

Reservoir Characteristics and Controlling Factors of Devonian in Guizhong Depression

Wang Jian

(ExperimentalTestingInstituteofPetroChinaXinjiangOilfieldCompany,Karamay,Xinjiang834000,China)

Abstract:Devonian of Guizhong Depression has the unique “platform-basin-hill-slot” sedimentary system and the reservoir is complex which was less studied so far. To solve this problem, the characteristics of Devonian reservoirs in the region were studied on the basis of outcrop observations, rock and mineral identification, scanning electron microscopy and other data. Results showed that Devonian reservoir in Guizhong Depression mainly contained quartz sandstone, reef limestone, bioclastic limestone and dolomite. The reservoir space mainly contained the remaining pores between grains, biological pores within the framework, dissolution pores and pores between dolomite crystals. The quartz sandstone of lower Devonian had good physical property, which could be called crack-porosity reservoir. Carbonate reservoir in mid-upper Devonian had poor physical property and was low-porosity and low-permeability one, which could be improved by dolomitization. Major factors affecting reservoir development were sedimentary facies and diagenesis at late stage, including dolomitization and dissolution. The slope belt in northern and northeastern Guizhong Depression was favorable for reservoir.

Key words: Guizhong Depression; Devonian; pore type; reservoir property; controlling factor

桂中坳陷歷經50多年的油氣勘探，勘探程度逐漸增高，目前雖尚未發現工業油氣藏，但油氣顯示豐富，普查及鉆井發現油氣顯示達46處之多。同時在坳陷周邊發現早—中泥盆世的南丹大廠龍頭山生物礁和上林六卡等多處古油藏。……