陳文峰
長江大學(xué)地球環(huán)境與水資源學(xué)院,湖北武漢430100
中石化江漢油田分公司勘探開發(fā)研究院,湖北武漢130223
?
新溝油田新溝嘴組下段Ⅱ油組泥質(zhì)白云巖類儲層儲集物性及含油性
陳文峰
長江大學(xué)地球環(huán)境與水資源學(xué)院,湖北武漢430100
中石化江漢油田分公司勘探開發(fā)研究院,湖北武漢130223
[摘要]運用多種技術(shù)手段,從基質(zhì)孔隙和裂縫兩方面分析了新溝油田泥質(zhì)白云巖類儲層的儲集空間類型。結(jié)果表明:新溝嘴組下段Ⅱ油組泥質(zhì)白云巖類儲層巖性復(fù)雜,主要發(fā)育白云巖、泥質(zhì)粉砂巖、硬石膏巖、泥巖以及少量巖屑砂巖等,白云巖多具泥晶結(jié)構(gòu);泥晶白云巖儲集空間以白云石晶間孔為主,粉砂巖儲集空間以粒間孔為主,具中、高孔-特低滲特征。其含油量與孔隙度表現(xiàn)出線性增加和高值穩(wěn)定的兩段式特征,以10%為界,孔隙度高于10%的儲層含油量較高,適合進行壓裂。
[關(guān)鍵詞]泥質(zhì)白云巖;儲集空間;新溝油田;含油性;壓裂
江漢盆地鹽間白云巖儲層一直是研究的熱點和難點[1~3]。長期以來,受勘探開發(fā)技術(shù)的限制,一直缺少大的突破。近年來,隨著非常規(guī)油氣思想的引入及勘探開發(fā)技術(shù)的不斷創(chuàng)新[4~12],江漢油田也開始對新溝油田進行非常規(guī)油氣勘探開發(fā)。
1區(qū)域地質(zhì)特征
圖1 研究位置示意圖
2儲集層巖石學(xué)特征與儲集空間類型
2.1泥質(zhì)白云巖類儲層礦物組成
2.2儲集類型及孔隙特征
2.2.1儲集類型
通過對研究區(qū)內(nèi)的取心井系統(tǒng)開展鑄體圖像、掃描電鏡等分析測試,認(rèn)為泥晶白云巖儲層主要發(fā)育白云石晶間孔,粉砂巖儲層主要發(fā)育粒間孔,其次為微裂縫。泥晶白云巖中白云石粒徑多為2~4μm,孔徑介于0.1~2μm;而層間縫和微裂隙縫寬多為0.2~10μm。粉砂巖儲層中孔隙分布受膠結(jié)作用影響,無-弱膠結(jié)處發(fā)育粒間孔隙,孔徑區(qū)間主要分布于5~25μm(圖2)。
圖2 掃描電鏡下孔隙類型典型照片
從巖心觀察裂縫統(tǒng)計結(jié)果(表1)來看,整體上裂縫較發(fā)育,包括水平縫和高角度縫2種。其中水平縫較為細(xì)小,縫寬基本在2mm以下,多以紋層形式發(fā)育,在掃描電鏡也可觀察到少量層間縫和微裂隙,縫寬0.2~10μm。同時還發(fā)育有大量的高角度縫,裂縫寬度2~20mm,長度不等,多被石膏充填,裂縫線密度分布在0.3~2.0條/m之間(圖3)。
表1 不同巖石儲集空間類型頻率統(tǒng)計表
圖3 Ex泥質(zhì)白云巖類儲層各類裂縫發(fā)育特征
2.2.2孔隙特征
總體來看,Ex泥質(zhì)白云巖類儲層為中、高孔-特低滲儲層,多數(shù)裂縫發(fā)育,但部分微裂縫被石鹽或硬石膏完全充填,基本無滲流能力,是需要進行壓裂才能獲取產(chǎn)能的儲層。
表儲層孔隙結(jié)構(gòu)特征參數(shù)表
表3 新3井不同巖類孔隙結(jié)構(gòu)參數(shù)統(tǒng)計表
2.3泥質(zhì)白云巖類儲層含油性及與其儲層物性關(guān)系
江漢盆地Ex泥質(zhì)白云巖類儲層孔隙中大面積含油。在裂縫被石膏完全充填層段幾乎不含油,如新4井1067.99~1084.34m井段儲層巖性為泥晶白云巖,發(fā)育一條長40μm的裂縫,裂縫內(nèi)部被硬石膏充填,熒光照射無顯示。但在部分裂縫不發(fā)育的泥質(zhì)白云巖類儲層,發(fā)育晶間孔隙和粒間孔隙,孔隙內(nèi)普遍含油,如新3井的1376.42~1396.60m井段、1414.98~1425.00m井段,通過熒光觀察,發(fā)綠黃色、黃綠色中暗光,局部泥質(zhì)含量較高,呈現(xiàn)中暗-暗光條帶,偶見細(xì)小發(fā)綠黃色、淡黃白色中亮光的片狀有機質(zhì)紋層,屬富含沉積有機質(zhì)的烴源巖類,具有典型的源儲一體致密油特征[1]。
根據(jù)國內(nèi)外致密油開發(fā)的一般規(guī)律,一般要求商業(yè)開發(fā)的致密油層段含油率要大于100mg/g[6]。在該地區(qū),泥質(zhì)白云巖類儲層含油性的大小與孔隙度之間的關(guān)系不同于常規(guī)砂巖儲層的正相關(guān)關(guān)系,而是表現(xiàn)為兩段式曲線特征。即在孔隙度<10%時,其含油率普遍低于120mg/g,且隨孔隙度的增加而逐漸增大,當(dāng)孔隙度>10%時,其含油率增加緩慢,基本穩(wěn)定在較高水平,含油率可達150mg/g。
3結(jié)論
2)泥質(zhì)白云巖類儲層中泥晶白云巖儲集空間以晶間孔為主,粉砂巖儲集空間以粒間孔為主,具中、高孔-特低滲儲層特征。
3)以10%為界,當(dāng)孔隙度低于該值,含油量呈線性增加;孔隙度高于該值,則在相對高值處穩(wěn)定增長。
[參考文獻]
[1]熊智勇,吳世強,王洋,等.江漢鹽湖盆地鹽間泥質(zhì)白云巖油藏地質(zhì)特征與實踐[J].地質(zhì)科技情報,2015,34(2):181~187.
[2]蒲秀剛,韓德馨,許懷先,等.鹽間非砂巖油藏中原油的均質(zhì)性與非均質(zhì)性研究[J].石油實驗地質(zhì),2002,24(4):359~363.
[3]方志雄.潛江鹽湖盆地鹽間沉積的石油地質(zhì)特征[J].沉積學(xué)報,2002,4(4):34~36.
[4]鄒才能,陶士振,袁選俊,等.“連續(xù)型”油氣藏及其在全球的重要性:成藏、分布與評價[J].石油勘探與開發(fā),2009,36(6):669~680.
[5]Schmoker J W.Resourceassessment perspectives for unconventional gas systems[J].AAPG Bulletin,2002,86(11):1993~1999.
[6]Jarvie D M,Hill R J,Ruble T E,et al.Unconbentional shale-gas systems:The Mississippian Barnett Shale of north-central Texas as one model for themogenic shale-gas system[J].AAPG Bulletin,2007,91(4):475~499.
[7]林森虎,鄒才能,袁選俊,等.美國致密油開發(fā)現(xiàn)狀及啟示[J].巖性油氣藏,2011,23(4):26~28.
[8]鄒才能,朱如凱,吳松濤,等.常規(guī)與非常規(guī)油氣聚集類型、特征、機理及展望——以中國致密油和致密氣為例[J]. 石油學(xué)報,2012,33(2):173~187.
[9]賈承造,鄒才能,李建忠,等.中國致密油評價標(biāo)準(zhǔn)、主要類型、基本特征及資源前景[J]. 石油學(xué)報,2012,33(3):343~350.
[10]楊華,李士祥,劉顯陽. 鄂爾多斯盆地致密油、頁巖油特征及資源潛力[J]. 石油學(xué)報,2013,34(1):1~11.
[11]杜金虎,何海清,楊濤,等.中國致密油勘探進展及面臨的挑戰(zhàn)[J].中國石油勘探,2014,18(1):1~9.
[12]張君峰,畢海濱,許浩,等.國外致密油勘探開發(fā)新進展及借鑒意義[J]. 石油學(xué)報,2015,36(2):127~137.
[13]張建榮,蘇葦,陳立欣,等. 江漢盆地新溝嘴組碳酸鹽巖油藏特征及開發(fā)技術(shù)[J]. 石油天然氣學(xué)報(江漢石油學(xué)院學(xué)報),2013,35(10):116~120.
[編輯]鄧?yán)?/p>
Performance Evaluation on JK-1002 High Temperature Carboxymethyl Gum Fracturing Fluid and Its Application in Jilin Oilfield
Xu Zhandong, Dai Yanwei, Li Lishu
(FirstAuthor’sAddress:DownholeServiceCompany,DaqingDrillingandExplorationEngineeringCorporation,PetroChina,Songyuan138000,Jilin,China)
Abstract:The Shuangtuozi, Xiaohelong and Changling Gas Fields developed by Jilin Oilfield were characterized by complex lithology, deep burial, high formation temperature, difficult for fracturing reconstruction. In view of these characteristics, the JK-1002 high temperature carboxymethyl gum fracturing fluid was studied. The fracturing fluid had good temperature resistance and shear resistance. In the laboratory test, JK-1002 high temperature carboxymethyl hydroxypropyl guar gum fracturing fluid was contrasted with hydroxypropyl guar gum fracturing fluid,in friction,gel breaking, suspended sand and viscoelasticity, the JK-1002 high temperature carboxymethyl guar gum fracturing fluid was better than that of the hydroxypropyl guar gum fracturing fluid. In the period of 2012 to 2013, JK-1002 high temperature carboxymethyl gum fracturing fluid was used in 42 natural gas wells in Jilin Oilfield. Injection of fracturing fluid is 143912m3, the support agent is 19374m3, the operation pressure is stable, the development effect is good, and it obtains wide application. By using variety of technical means, the space type of argillaceous dolomite reservoir in Xingou Oilfield was analyzed from the aspects of matrix pores and fractures. The result indicated the lithology of the dolomite reservoir in 2(nd) oil formation of Xingouzui Formation was complex, in which dolomite, pelitic siltstone, anhydrock, mudstone and a small quantity of litharenite was mainly developed, and most of the dolomite had micritic structures. The reservoir space of micritic dolomite was mainly filled with intercrystalline pores, and the siltstone reservoir space was dominated by intergranular pores, which possessed the characteristics of medium to high porosity and extra-low permeability. The oil content and porosity present two-stage characteristics of linear increase and high value stability. The reservoir with porosity higher than 10 percent, its oil content is higher, and it’s suitable for fracturing.
Key words:JK-1002 high temperature carboxymethyl gum; fracturing fluid; Jilin Oilfield argillaceous dolomite;reservoir space;Xingou Oilfield;oil-bearing property;fracturing
Reservoir Physical Property and Oil-bearing Property of Argillaceous Dolomite of Xingouzui Formation in Xingou Oilfield
Chen Wenfeng
(Author’sAddress:SchoolofEarthEnvironmentandWaterResources,YangtzeUniversity,Wuhan430100,Hubei,China;ResearchInstituteofPetroleumExplorationandDevelopment,JianghanOilfieldCompany,SINOPEC,Wuhan430223,Hubei,China)
[中圖分類號]TE122.2
[文獻標(biāo)志碼]A
[文章編號]1673-1409(2016)8-0011-04
[作者簡介]陳文峰(1983-),男,碩士生,主要從事石油地質(zhì)綜合研究, wenfengchen@163.com。
[基金項目]國家自然科學(xué)基金項目(41503034);油氣資源與探測國家實驗室開放課題基金項目(PRP/Open-1509);中國石油化工股份有限公司項目(P11070)。
[收稿日期]2015-12-09
[引著格式]陳文峰.新溝油田新溝嘴組下段Ⅱ油組泥質(zhì)白云巖類儲層儲集物性及含油性[J].長江大學(xué)學(xué)報(自科版),2016,13(8):11~14,69.