Promote new progress in oil and gas exploration in key basins

The fault depression is located on the east side of Songliao basin and distributed in northeast direction. Graben is controlled by NE-trending faults and cut by NW-trending faults. The tertiary system as a whole is long trough-shaped, and the basement fluctuates along the long axis. From north to south, it includes Tangyuan fault depression, Fangzheng fault depression, Shengli town fault depression, Lan Shu fault depression, Chaluhe fault depression, Dagushan fault depression and Yitong fault depression. Daqing oilfield and Jilin oilfield are located in Fangzheng fault depression and Yitong fault depression.

1. Tangyuan fault depression

The source rocks of Cretaceous petroleum system in Tangyuan fault depression are Cretaceous lacustrine dark mudstone, and the overlying fan delta and lacustrine fan sand bodies of Cretaceous Wuyun Formation, Xin 'ancun Formation, the second member of Dalianhe Formation and the second member of Baoquanling Formation can be used as their reservoirs, and the thick mudstone of Cretaceous Dalianhe Formation and Baoquanling Formation can be used as their caprocks. Oil generation period began after Wuyun Formation was deposited, and gas generation period has started since Wuyun Formation was deposited. The formation of lithologic traps is mainly in the sedimentary period of Dalianhe Formation and Baoquanling Formation, that is, the continuous fault depression period and fault depression transformation period of Tangyuan fault depression. The formation of structural traps mainly occurred in the four stages of tectonic movements at the end of Cretaceous, Dalianhe Formation, Baoquanling Formation and Tertiary. The key periods of Cretaceous petroleum system are the end of Dalianhe Formation, Baoquanling Formation and Tertiary. Due to the tectonic movement at the end of Baoquanling Formation and the end of Tertiary sedimentation, oil and gas reservoirs may be destroyed.

Figure 5-9 Comprehensive Evaluation Diagram of Tang 1 Well Reservoir

Well Tang 1 is a regional exploration well in Dongxing syncline of Tangyuan fault depression (Figure 5-9). Drilling and coring of the whole well shows oil-soaked sandstone 0.30m, oil-stained sandstone 0.33m, oil-stained sandstone 0.60m, fluorescent sandstone 9.66m and fluorescent sandstone 2.12m; ; Debris logging shows oil-bearing sandstone 1, fluorescent sandstone 64 and fluorescent glutenite 75. Gas logging shows abnormality in 5 1 layer. Tang 1 well logging * * * explains that the gas-water layer is 1 and the thickness is12.0m.: ; The suspicious gas layer is 1 and the thickness is1.4m; ; There are 9 layers of poor oil layers with a thickness of 36.0m; Oil and water are in the same layer, with a thickness of 6.6m；; There are 4 oil-bearing water layers with a thickness of14.0m. According to logging and mud logging interpretation data, 1 12, 1 13, 12 1. After fracturing in 239 ~ 240 layers of Xin 'ancun Formation+Wuyun Formation and Dalianhe Formation 12 1 and 124 layers, oil flowers are seen. Oil and gas display in large section of Tang 1 well. After fracturing in Xin 'ancun Formation 12 1 and 124, oil flowers are seen, and a small amount of oil flow is seen in Wuyun Formation 239 and 240, which shows that Tangyuan fault depression has a good exploration prospect.

2. Fangzheng fault depression

Similar to Tangyuan fault depression, the source rocks of Cretaceous petroleum system in Fangzheng fault depression are Cretaceous lacustrine deposits, and the overlying Cretaceous, Paleogene Wuyun Formation, Xin 'ancun Formation, Shangdalianhe Formation and Shangbaoquanling Formation can be its reservoirs, while Cretaceous, Lower Paleogene Dalianhe Formation and Xiabaoquanling Formation can be its caprocks. Oil generation began after Wuyun Formation was deposited. The gas generation period is Wuyun Formation.

The source rocks of Paleogene petroleum system in Fangzheng fault depression are Paleogene Wuyun Formation to Baoquanling Formation, and Wuyun Formation, Xin 'ancun Formation, Shangdalianhe Formation and Shangbaoquanling Formation can be used as their reservoirs, while Xialianhe Formation and Xiabaoquanling Formation can be used as their caprocks. The oil generation period is from the lower part of Dalianhe Formation to the present. The gas generation period is from the late sedimentary period of Xin 'ancun Formation to the present.

Whether Cretaceous or Paleogene, lithologic traps were mainly formed in the sedimentary period of Dalianhe Formation and Baoquanling Formation. The formation of structural traps mainly occurred in four tectonic movements at the end of Cretaceous, namely Dalianhe Formation, Baoquanling Formation and Neogene. The key periods of the two petroleum systems are the end of Dalianhe Formation, Baoquanling Formation and Paleogene. Due to the tectonic movement of Baoquanling Formation at the end of sedimentation and Tertiary, oil and gas reservoirs may be destroyed.

(2) Great Sanjiang area

Dasanjiang area includes Mesozoic and Cenozoic residual basins such as Sanjiang Basin, Jiamusi Basin, Boli Basin, Hulin Basin and Jixi Basin.

1. Hulin Basin

Hulin Basin is located in the east of Heilongjiang Province, with an area of 95 10km2, starting from the south slope of Wandashan in the north, reaching Xingkai Lake in the south, Mishan and Baoqing in the west and Wusuli River in the east. The basement of the basin is dominated by Paleozoic crystalline metamorphic rocks, and Mesozoic and Cenozoic strata are widely developed, including Upper Jurassic Peide Formation, Qihulin Formation, Xiayunshan Formation, Shangyunshan Formation, Zhushan Formation, Lower Cretaceous Dongshan Formation, Paleogene Hulin Formation, Neogene Fujin Formation and Daotaiqiao Formation.

Through the re-processing and interpretation of seismic data, this project points out that there is a deep depression in the west of Qihu Linhe sag, and Hu 1 well has been deployed and implemented. The cuttings logging of the whole well shows that there are 8 layers of fluorescent sandstone, 8 layers of fluorescent glutenite 1 layer, 5 layers of oil-bearing sandstone are found in sidewall coring, and gas logging shows that there are abnormal 104 layers. Comprehensive evaluation shows that Hu Yi member belongs to medium-good source rock and has reached a mature stage. The reservoir has poor physical properties, and the comprehensive evaluation shows that it is low porosity and permeability. Applicable to S 1- 1 (No.188,No. 189), C2- 1 (No.183), S3- 1 (No./. No. 188 andNo. 189 have a daily output of 0.058 tons, and the oil test conclusion is that it is a low-yield reservoir; The daily oil production of 183 layer is 0.00 1t, and the oil test conclusion is dry layer; The daily oil production of 174i and 183 is 0.5 1 1t, and the oil testing conclusion is low. Oil-source correlation confirms that the crude oil of Hu 1 well comes from mudstone of Hu 1 member. Well Hu 1 shows good oil and gas display, and a small amount of oil flow is obtained in the oil fracturing test for the first time, which proves that Hulin Basin is a new oil-bearing basin in Paleogene and a favorable area for breakthrough.

2. Jixi Basin

Jixi Basin is located in the southeast of Heilongjiang Province, with an area of 3780km2. The basin is a Mesozoic-Cenozoic tectonic basin with complex basement properties, which is mainly composed of upper Archaean Mashan Group, upper Paleozoic Heilongjiang Group deep metamorphic rocks, migmatite and upper Paleozoic shallow metamorphic rocks. There is an east-west Ma Ping fault and an east-west basement uplift in the middle of the basin, which divides the basin into two zones: north and south. Sedimentary caprocks are mainly composed of Didao Formation, Chengzihe Formation, Muling Formation and Dongshan Formation of Lower Cretaceous, Houshigou Formation and Hailang Formation of Upper Cretaceous, Yongqing Formation of Paleogene and Daotaiqiao Formation of Neogene.

In this project, Jidd6 well was implemented in Didao sag and seismic survey lines were deployed. Good dark mudstone and 5.34m fluorescent, oil-stained and oil-spotted sandstone were found in Chengzihe Formation and Muling Formation. The type of organic matter is mainly Type III, with high maturity, which is reflected in cracked gas and dry gas stage, which proves that oil and gas generation and migration have taken place in the northern part of Jixi Basin, which has the conditions for oil and gas accumulation, indicating that this area has certain exploration potential. Non-seismic geophysical and seismic data show that the deepest part of the basin is in the northern sag, especially Didao sag, indicating the thickness of the target layer in the northern sag. It is considered that Didao sag in the northern Jixi basin is a favorable zone for oil and gas exploration.

3. Sanjiang Basin

Sanjiang Basin is located in the northeast of Heilongjiang Province, starting from Jiamusi in the west, Wusuli River and Wandashan in the east, Heilongjiang in the north and Shuangyashan Basin in the south. It is located in the Sanjiang Plain where Heilongjiang, Songhua River and Wusuli River meet, distributed in the northeast, and connected with the central part of amur river Valley in Russia, with an area of about 56,640 square kilometers in Russia and 33,730 square kilometers in China. There are two depressions in the east and west of Sanjiang Basin, Suibin sag in the west has a high degree of exploration, and Qianjin sag in the east has a low degree of exploration. There are Jurassic, Cretaceous and Tertiary in Naolihe sag in the south of Qianjin sag, and Cretaceous and Tertiary are mainly developed in Nongjiang sag in the north of Qianjin sag, followed by Upper Cretaceous. At present, China Petrochemical has found a good hydrocarbon-generating rock series in Tertiary, which shows that

③ Dayangshu Basin

Dayangshu Basin is located in Arong Banner-Oroqen Autonomous Banner in the east of Inner Mongolia Autonomous Region and gannan county, Heilongjiang Province, with an area of 15640 km2. Only the southern depression has an area of nearly 5000km2 with the basement buried more than 3,000 m, and the oil resources are 1.5 1× 108t. The Lower Cretaceous Longjiang Formation, Jiufengshan Formation and Ganhe Formation are distributed from bottom to top in Dayangshu Basin, among which Jiufengshan Formation is the most widely distributed. Faults are developed in the basin, with a series of normal faults in the northeast, which descend towards the deep depression of the basin in a stepped way, forming a structural pattern in which the basin is gentle in the west and steep in the east, deep in the south and shallow in the north, and depressions and uplifts alternate from south to north. Generally speaking, it is a structural pattern of three depressions and two uplifts. From south to north, there are southern sag, southern uplift, central sag, central uplift and northern sag in turn. The main exploration workload is 1∶ 1 gravity and magnetism, 2D seismic exploration 1 402.4km, and 4 shallow geological wells and1parameter wells are drilled.

Many oil and gas displays have been seen in the field outcrops of Dayangshu Basin, and good oil and gas displays have also been seen in two wells. There are various types of oil-bearing strata and reservoirs, including volcanic lava reservoirs, glutenite reservoirs and basement granite fractured reservoirs. Well Yang D 1 is a volcanic oil and gas well drilled in the high part of local structure in the central depression zone of the southern depression. When drilling to 526 ~ 530 m, the oil-bearing strata are pores of Ganhe Formation and broken andesite basalt, and the broken oil-bearing basalt with a thickness of about 2.5m is seen at 641~ 644 m. The crude oil analysis results show that it is normal mature light oil. In Yang Shen 1 Well, 8 oil layers are found in the interval of 560 ~ 2038.0m, and the oil-bearing lithology includes basalt, tuff, siltstone and diabase. The test results show that the daily oil production is 0.0 17t and the daily gas production is 74m3. Well Yang 1 is located in Yulintun sag in the south of the sag. Green-gray oil trace andesite is seen at1908 ~1913m, and gas logging shows that gray glutenite is seen at 2 166 ~ 2 167m. Logging interpretation shows that there is a poor oil layer with a thickness of 6.4m and two suspicious oil layers with a thickness of 46.8m in the upper part of Jiufengshan Formation, which is equivalent to two poor oil layers and one suspicious oil layer in the upper part of Yang Shen 1 Jingjiufengshan Formation. Mudstone 1 8.4m is seen in the upper part of Yang1Well Jiufengshan Formation, and the largest single layer is10.5m. The mudstone has high organic matter content, and the source rock parent material type is mainly sapropelic, with high organic matter transformation degree, which is in a mature stage. The Jiufengshan Formation is mainly developed with pores and fractured reservoirs, with uneven distribution of pores and fractures, irregular shapes and poor connectivity, and good volcanic reservoirs exist locally. The two exploration wells are 20 kilometers apart, and oil and gas show is seen in Jiufengshan Formation, which shows a good exploration prospect in the south of Dayangshu Basin.