Chief Geologist: Xiangzeng Wang Shaanxi Yanchang Petroleum (Group)Co.,Ltd. Sept.2012

Transcription

1 Chief Geologist: Xiangzeng Wang Shaanxi Yanchang Petroleum (Group)Co.,Ltd. Sept.2012

2 Contents I. The exploration discovery of continental shale gas by Yanchang oilfield II. The geology of continental shale gas in Ordos Basin III. The key technologies of continental shale gas in Yanchang oilfield IV. The main results and understanding

3 塔木盆地里准噶尔盆地地盆鄂尔多斯地盆松辽地盆四川盆地湾渤海盆地塘羌柴盆地达木盆地东海盆地珠江口盆地莺歌海二连盆地盆地吐哈河盆地西走廊群银盆额地海拉尔盆地塔木盆地里准噶尔盆地地盆鄂尔多斯地盆松辽地盆四川盆地湾渤海盆地塘羌柴盆地达木盆地东海盆地珠江口盆地莺歌海二连盆地盆地吐哈河盆地西走廊群银盆额地海拉尔盆地吐哈盆地 P-J 松辽盆地 K 准噶尔盆地 P-J 渤海湾盆地 E Ordos Basin, T ⅰ The distribution of continental shale gas in Ordos Basin, China The total amont of Chinese continental shale gas resources are m 3, the recoverable ones are m 3. Mainly distributing in the 5 basins in the north of China, The continental shale gas occupies an area of about 20~ km 2, among of which the amont in Ordos Basin is m 3. Our Yanchang Petroleum (Group) conducted the research on basic geology and key technologies around the Ordos Basin shale gas.

4 ⅱ Exploration discovery of continental shale gas, Yanchang petroleum Liuping 177, the first continental shale gas well in China, succeeded in gas flow after fracturing! On April 2011, the shale in Chang 7 member of Liuping 177 was tested and got gas flow of about 2350m3 per day, becoming the first continental shale gas well in China. 地层 系组段 自然电位 自然伽马 深度 ( m) 1440 岩性 全烃曲线 0 10 声波时差 综合解电阻率释结果 长 1460 fracturing interval 三 延 7 段 1480 含气 m ; 叠 长 1500 black shale 组 含气 系 1520 长 8 段 1540 Gas logging peak value : 9.09% Liuping 177

5 ⅱ Exploration discovery of continental shale gas, Yanchang petroleum following Liuping 177, the six wells such as Liuping 179 etc. succeeded in igniting one after another. The gas wells distribute in sheet shape in the map,and gradually take shape.we discovered the continental shale gas. Map of Test Well Location of Mesozoic Yanchang Group

6 Contents I. The exploration discovery of continental shale gas by Yanchang oilfield II. The geology of continental shale gas in Ordos Basin III. The key technologies of continental shale gas in Yanchang oilfield IV. The main results and understanding

7 I. GEOLOGY II. SOURCE ROCK formation sedimentary system and facies tectonic characteristics thickness of shale TOC thermal evolution degree III. RESERVIOR lithology Heterogeneity characteristics Rock electrical characteristics mineral composition shale property and gas-bearing characteristics

8 ⅰ Geology Formation and Sedimentary Characteristics Longitudinally Series of target layers overlapping Marine-continental Transitional Facies, continental dark mudstone layers of Benxi - Shanxi Group, upper palaeozoic Permian & Carboniferous Continental dark mud shale layers of Mesozoic Triassic Yanchang Group sedimentary characteristics Ordos Basin is a multi-cycle superposed basin. It developed a Marine sedimentary system during the earlier period of Late Paleozoic, and continental sedimentary system after the late Paleozoic Permian, among of which the warm wet climate and lacustrine deposit of Middle- Late Triassic provide the favorable conditions for the shale gas. TRIACCIC PERMIAN 柱状图 CONTINENT AL Marine-continental Transitional CARBONIFEROUS

9 ⅰ Geology Sedimentary characteristics SEDIMENTARY FACE CHANG1 The sedimentary system of Late Triassic is inland lake, the facies of upper Triassic include fluvial, lacustrine and delta facies. The organic-rich shale, deposited in lacustrine facies during Chang 9-Chang 7, provides the good conditions for the shale gas generation. UPPER TRIASSIC CHANG2 CHANG3 CHANG4+5 CHANG6 CHANG7 CHANG8 CHANG9 CHANG10 RIVER DELTA LAKE RIVER

10 ⅰ Geology Sedimentary characteristics Sedimentary Map of Chang7 of Yanchang Formation in Triassic in Ordos Basin Sedimentary Map of Chang9 of Yanchang Formation in Triassic in Ordos Basin The deep lacustrine facies of upper Triassic in Ordos Baisn distributed in NW-SE, with an area of about km 2.

11 ⅰ Geology Tectonic Characteristics The formation dip to west with no folds and faults et al. In the internal part of Ordos Basin. The structural feature maintained good conditions for the gas reservoir forming. Chang7 of Yanchang Formation buried 1000 ~2000m undergroud. Top surface structure of Chang7 of Yanchang Formation in Triassic in Ordos Basin

12 ii.source ROCK Thickness of shale Spreading in NE-SW, the dark shale was sedimented in deep lacustrine facies in upper Triassic Chang 7 in 鄂尔多斯盆地三叠系长 7 页岩厚度图 延长组长 7- 长 9 对比剖面 ( 东 - 西 ) the southeast of Ordos Basin. The thickest shale layers are up to 100m, the thickness of single layer is between 30-60m.

13 ii.source ROCK TOC Higher TOC 6 样数 ( 个 ) 0 样数 ( 个 ) TOC(%) 长 7 页岩 TOC 统计直方图 TOC(%) 长 9 页岩 TOC 统计直方图 TOC of Chang 7: 0.34%~25.46%, Peak Value: 3%~5%; TOC of Chang 9: 0.65%~25.90%, Peak Value: 1%~8%.

14 ii.source ROCK Thermal Evolution Degree Moderate Organic Maturity 数量 10 8 长 7 段 Ro 样品分布深度 : m 数据点 :24 个 Ro ( %) Ro= 0.5 % Ro= 1.4 % 6 4 长 9 段 Ro 样品分布深度 : m 数据点 :11 个 深度 (m) Ro(%) 长 7 段 Ro( %) 长 9 段 Ro( %) a. Ro of Chang 7 & Chang 9:0.5 %~1.4%, Peak Value: 0.7%~1%; in the maturity and moisture stage b. Ro increases with the depth.

15 iii. Reservoir lithology The lithology of Chang 7 of Triassic Yanchang Group in Ordos Basin is black mudstone or shale rock, argillaceous siltstone, silty mudstone, siltstone and lamellation development.

16 iii. Reservoir Heterogeneity characteristics Longitudinally, lamina and shale are interbedded in the mudstone segment of Yanchang Goup, the lamina shape in lens, shale reservoir show strong heterogeneity characteristics. 47 laminae can be at most developed in each shale rock layer. 深度 ( m) 岩性 x4 lamina lamina lamina lamina shale shale lamina

17 iii. Reservoir Rock electrical characteristics 柳评 180 段 深度 ( m) GR AC R The log response of shale rock is characterized by high GR, DT and RT. 长 7 长 8 长 m 20m

18 iii. Reservoir mineral composition for reservoir The clasic constitute of shale rock mainly are quartz, syenite and mica. the cement is calcite, quartz, clay mineral. The total content of brittle mineral averages 44.3%. The clay mineral averages 56%. The average content of mixed-layer minerals in illit account for 47.6% of clay mineral content mixed layers 石英长石伊利石蒙脱石绿泥石高岭石黄铁矿碳酸盐 % 20% 40% 60% 80% 100% reservoir mineral constitute clay mineral constitute

19 iii. Reservoir The pore structure of reservoir ( 个 ) 中生界长 7 段 + 长 9 段泥页岩平均孔径主要分布于 6 nm 7 nm, 均值为 7.2 nm 平均孔直径 (nm) 国际理论和应用化学协会 (IUPAC) 孔隙分类 (RouqueRol et al.,1994);<2nm 微孔隙,2~50nm 中孔隙,>50nm 宏孔隙 The pore diameter of shale samples is 4-10nm, with single peak type of pore size distribution. According to the international standard, the pore of shale in research area belongs to medium porosity.

20 iii. Reservoir Pore structute for reservoir The amount of micropore were developed in organic matter of Mesozoic shale rock reservoir, which provided conditions for shale gas storage and accumulation.

21 iii. Reservoir shale property The shale property of Yanchang Group is generally poor, with 1%-2.5% of porosity peak, 2% of average porosity and less than 0.01md of permeability.

22 iii. Reservoir Gas-bearing characteristics Isothermal adsorption: the maximum is 2.75 m 3 /t,generally up to 1 m 3 /t Comprehensive test reveals that the shale rock is rich in gas, the average content of gas is 1.64m 3 /t. Total gas content: m 3 /t Average: 1.64m 3 /t

23 iii. Reservoir Genetic type of shale gas -40 III1-35 II VI -30 I煤成气区 II油型气区 III碳同位素系列倒转混合区 IV IV δ 13 C3( ) -80 IV煤成气和油型气区 V煤成气 油型气和混合气 VI生物气和亚生物气 -70 VI V V IV -30 I I III2 III2 IV δ 13 C1 ( ) -20 II III1 δ 13 C2( ) 长 8伴生气长 2伴生气长 6伴生气长 7页岩气长 8页岩气长 9页岩气 The isotopic value of natural gas and methane in Mesozoic Yanchang Group is -53 ~-44 in Ordos Basin; that of ethane is -40 ~-32 ; that of propane is -30 ~-34. Genetic type of shale gas is comprehensively estimated to be low-maturity oil-type gas formed by initial cracking of sapropelic kerogen.

24 Contents I. The exploration discovery of continental shale gas by Yanchang oilfield II. The geology of continental shale gas in Ordos Basin III. The key technologies of continental shale gas in Yanchang oilfield IV. The main results and understanding

25 i. Horizontal drilling and completion ii. Hydraulic fracturing iii. Treatment and reuse of fracturing flowback fluid

26 i.technology of horizontal drilling and completion Main Problems Poor stability of sidewell in open hole section high content and strong sensitivity of formation clay mineral obvious anisotropy of rock mechanics More difficult for well cementation Risk profile of collapse pressure Well leakage will be easily occured due to low pressure of formation, development of microfracture; Perforation and large-scale hydraulic fracture demand even higher intensity of cement stone; Drilling fluid of oil-base influence the quality of Cement ring interface cementation.

27 i.technology of horizontal drilling and completion a.technology of sidewell stability of long open hole section Evaluation on sidewell stability The evaluation on sidewell stability optimize drilling design and confirm mud scale. Technology of oil-base drilling fluid Oil base drilling fluid: low filtration, strong inhibition, good sealing, and the increasing of reservoir protection 坍塌压力 (g/ cm^3) N070 E N085 E N100 E N115 E N130 E N145 E N160 E 井斜角 ( ) Map of varying pattern of Collapse pressure with well deviation and azimut Countermeasures for Drilling fluids

28 i.technology of horizontal drilling and completion Technology of well cementation The anti-gas-channeling foam cement slurry Measures Cement slurry system Improving interface cementation quality Improving displacement efficiency low density, high strength, anti-gaschanneling slurry system Efficient flushing fluid Centering casing Improving displacement rate Foam cement stone samples Cement slurry thickening curve Evaluation of cement stone strength Analysis of casing setting

29 ii. Hydraulic fracturing Main problems Strong reservoir heterogeneity Poor reservoir physical properties Sedimentary facies lateral change fast Low content of brittle mineral Low formation pressure High content of water-sensitive minerals Difficult for Hydraulic fracturing Difficult for Fracturing fluid flowback is Difficult for Reservoir protection is

30 ii. Hydraulic fracturing slickwater fracturing fluid with low damage, low friction Cleanup agent (YC-ZF-2), which can improve cleanup rate up to 70%. Anti-swelling agent (YC-FP-1 and YC-FP-2), which can improve anti-swelling rate up to 85% or more. Reduction agent (YC-YZ-1),which can reduce the pressure more than 15 MPa. 返排率 % # 2# 3# 4# 5# 6# 7# 8# 井号 Comparison chart of cleanup rate of different wells 防膨率 % YC-FP-1 YC-FP-2 YC- 复配 COP- 1 FY- FP- 4 防膨剂种类 Comparison chart of Anti-swelling rate by different agents Comparison chart of friction by reducing agents

31 ii. Hydraulic fracturing fracturing technologies technology of pretreatment before fracturing technology of muti-stage sand adding with high rate by pulse-type Using low-density proppant with muti-stage combination The scene of hydraulic fracturing Ceramic with Low density

32 ii. Hydraulic fracturing Technology of fracture evaluation Monitoring of interwells microseism fracturing Monitoring of surface microseism fracturing

33 iii.treatment and reuse of fracturing flowback fluid Main problems Fracturing flowback fluid contains additives and other pollutants, which can cause the risk of surface pollution. Water resources shortage is obvious in Ordos Basin. Huge water consumption lead the fracturing to be expensive.

34 iii.treatment and reuse of fracturing flowback fluid Resolution and Achievements Based on the technologies of micro-interface flocculation, catalytic oxidation, directional decoloring, strengthened solid-liquid separation, we designed the mobile fracturing flowback fluid recovery processing device independently,which adopts modular design and can realize arbitrary combination and switching between each module to according to the fracturing flowback fluid properties. The indoor experiment shows that the water quality of treated fracturing flowback fluid can reach recycling standard. YC-FC01 装置 1 号处理水样

35 Contents I. The exploration discovery of continental shale gas by Yanchang oilfield II. The geology of continental shale gas in Ordos Basin III. The key technologies of continental shale gas in Yanchang oilfield IV. The main results and understanding

36 i. The continental sedimentary basins possess shale gas potential Sedimentary facies change fast laterally Small-scale basin small distribution range The traditional understanding for continental shale reservoir Thickness unstability Relative young formation age Low degree of thermal evolution proximal deposit Poor reservoir physical properties The forming conditions for Shale gas is relative worse in continental than in marine basin.

37 i. The continental sedimentary basins possess shale gas potential. Based on the geological research, the thickness of single shale layer is about m, the average TOC is 3.65%, Ro is about 1.The micropores are developed in shale, and average porosity is 2%, the gas content averages 1.64 m 3 / t. The continental sedimentary basins have shale gas potential.

38 ii. Shale gas of Ordos basin belongs to low maturity oil-type gas Based on the analysis, we can get the geo-chemical paramaters of shale and shale gas for Triassic formation in Ordos basin : the vitrinite reflectance (Ro) of organic matter is 0.5%-1.4%, methane isotope values of natural gas is - 53 ~ - 44, ethane and propane isotope values are - 40 ~ - 32 and - 30 ~ - 34 separately. Shale gas type is oil-type gas with low maturity, which was generated by initial cracking of sapropelic kerogen.

39 iii. The continental shale reservoir can be fractured Continental shale reservoir fracturing is very difficult. The major reason is the difficulties of fracturing reconstruction, such as low content of brittle mineral, high content of clay mineral and fracturing fluid flowback. Through the research on fracturing fluid and fracturing technology, 8 Wells were fractured successfully, proving that continental shale reservoir can be fractured.

40 iv. The shale gas resource potential of Yanchang Petroleum Based on the resources evaluation parameters, such as the shale thickness, buried depth, gas content, the resources abundance and etc, two shale gas potential region of about 1850 km 2 can be optimized preliminary. Shale gas resource is about 5630 x 10 8 m 3. We can draw the conclusion that the continental shale gas has a good resource potential.

41 Epilogue Yanchang Petroleum is the birthplace of first onshore oil well in China. In 2011, the first continental shale gaswell was fractured successfully. We will be adhering to the spirit of "hard work, innovation" and the ideas of combining the independent innovation with introduction, digestion, absorption and reinnovation. At the same time, we will strengthen international exchanges and cooperation, share the development opportunities, join hands to tackle various challenges and achieve win-win cooperation and harmonious development,and make contributions for the human society development.

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