According to the seismic survey of Siwu, it is found that the Liu Zhuang structure (seismic line J 180, pile number 3 1450 North 190 m) at the high part of the slope has a trap area of about 1 1 km2, which belongs to the nose structure on the second step of the north slope of Sanhe Sub-sag and is separated by a fault.
1974 10, the 3007 drilling team once again took on the heavy responsibility of the main attack, and Dong 60 well was constructed on this structure. Upp has taken strict engineering measures for this purpose, and strengthened the comprehensive research work. In cooperation with Professor Yan Qinshang from the Department of Marine Geology of Tongji University, the sedimentary facies belt of Funing Formation in Well Dong 60 has been comprehensively studied.
Well Dong 60 was drilled to1152m, and when it entered the second member of Funing Formation, it encountered oil-bearing cuttings of gray marl and biolimestone, and immediately drilled holes for coring. According to the original records of my site, the whole process of this special lithologic section is as follows:
The depth of the well is 942m below the denudation surface of Dai Nan Formation, that is, it enters the fourth member of Funing Formation. In the 5 1m interval of165438+1189m, in addition to biolimestone, there are oil spots such as siltstone and silty sandstone, and oil-bearing and oil-bearing gas show strong fluorescence reaction. A total of 7 coring operations were conducted in the whole interval, and the core recovery rate mostly reached 100%. Comprehensive lateral logging after completion shows that the total thickness of oil layer is 26.4m, including oil-bearing oil sand11.5m, oil-bearing marl and biolimestone of 8.3m, and marl and sandstone interbedded with oil of 6.6m. In order to further define oil and gas layers, 68 coring wells were drilled in 5 intervals, and 35 wells were successful. Analysis of sidewall coring in 12 layer shows that the oil content is 40.86%, the water content is 27.07%, the porosity is 26. 13%, and the permeability is152.53 ~175.46mdarcy. Logging interpretation: oil content is 54.5%, porosity is 2 1.8%, and the highest permeability is 203.86 millidarcy. This well has excellent data and the best geological logging quality in Dong Zihao well. When I took out the biological limestone core, I only saw something that lit up the crystal, so I concluded that it was a trace of gas leaching from the gas-bearing layer. The study is divided into two tests: the first drilling in Funing Formation 1 section 1229.03 ~ 1332 m, and the daily crude oil production of 12 is 7.9 1 m3. The second time, on April 30th of the following year, the second member of Funing Formation biolimestone1151.2 ~1153.74m,1138.0 ~/. The open flow rate is 34 1 000 cubic meters, and the daily production is stable at 260,000 cubic meters. The natural gas field in Liu Zhuang, northern Jiangsu Province was discovered for the first time, and the second member of Funing Formation was confirmed as a new oil and gas producing zone in northern Jiangsu Province, which played an important role in putting forward equal emphasis on oil and gas for future exploration and deployment in northern Jiangsu Province. During the test, Zhang, Zhang, Wang Guixin and other scientific and technical personnel of the Fifth Academy of Science and Technology and the workers of the field trial production team worked day and night to contribute to the venting of Dong 60 well.
Thereafter, on1March, 97515th, Up3206 drilling team drilled Dong 64 well in Liu Zhuang structure, in the second member of Funing Formation, namely, biolimestone140.0 ~146.
The development of Liu Zhuang gas field has been commended by State Geological Bureau, Petroleum Geological Bureau, Jiangsu Provincial Party Committee and Government, Jinhu County Committee and Jiangsu Petroleum Exploration Command. Jinhu County Committee also specially hosted a banquet for our main battle personnel, so that everyone could taste the delicious hairy crabs in Hongze Lake.
Speaking of Hongze Lake, there is a historical story:
In 6 16 AD, Yang Di Yang Guang took a dragon boat from Luoyang to the south of the Yangtze River, which was a dry season. He passed through the kettle-broken pool and met with heavy rain, so he changed the kettle-broken pool to Hongzepu, which was called Hongze Lake in the Tang Dynasty. This is the origin of the name Hongze Lake.
According to historical records, Sizhou City was built on the southwest bank of Hongze Lake in the north weekend, becoming a north-south transportation hub with bustling streets and magnificent pagodas. During the Jian 'an period of the Song Dynasty (A.D.1127 ~1130), it was destroyed by a big fire. During the more than 240 years from the second year of Ming Yingzong orthodoxy to the nineteenth year of Qing Emperor Kangxi, there were four tragic disasters that flooded Sizhou City, so that the ancient city of Sizhou was swallowed up by floods.
1966, there was a drought in the Huaihe River Basin, the Huaihe River was cut off, and Hongze Lake dried up to the bottom, revealing the ruins of Sizhou City in the southwest of the lake.
Hongze Lake is connected with Jinhu Depression. At the same time of oil and gas exploration in Jinhu, in order to expand the results, the Sixth Geophysical Exploration Brigade set up a lake seismic team to conduct seismic investigation on Hongze Lake.
On July 27th, 1976, Up3203 drilling team completed drilling Dong 66 well in Huang Zhuang structure of Jinhu sag, and drilled into the second member of Funing Formation with a depth of 2006.3 ~ 2009.88 meters. On May 5th of the following year, an attempt was made to obtain an industrial oil flow, with a maximum daily output of crude oil 12.42 cubic meters, and Huang Zhuang Oilfield was discovered.
Previously, drilling team UP32333 drilled well Dong 45 in Biantang structure of Jinhu sag, and drilled oil layers at181.8 ~1817.34 m in the second member of Funing Formation. After acidizing, fracturing and other stimulation measures, it reached 1979 in August.
So far, Wupu and Siwu discovered Liu Zhuang gas field and two oil fields in Jinhu sag, which greatly improved the oil and gas evaluation of the sag and marked a great victory since they participated in the oil battle in northern Jiangsu.
In the past five years, Upp has drilled 82 wells in northern Jiangsu with a total footage 197833.07 m, including 74 deep wells with a footage 190587.72 m, including the drilling workload in Hai 'an sag and Yanfu sag.
65438-0977, Liu Zhuang gas field was put into development immediately after being handed over to Jiangsu Petroleum Exploration and Development Headquarters, mainly for gas production. 1985 annual output of natural gas170,000 cubic meters, 4000 tons of crude oil.
When Upp came to northern Jiangsu from Jingzhou, Jianghan, he wanted to create more brilliant achievements in northern Jiangsu with super-high-yield experience, but he failed to do so.
As Tang Youzeng, a poet in Qing Dynasty, said, "The terrain is natural and the Chu River is vast, so it is difficult to borrow Jingzhou since ancient times." As far as oil flow output is concerned, due to various restrictions of objective geological conditions in Subei Basin, the output of a single well has never exceeded 1000 tons/day.
However, the Subei basin has its own geological characteristics, and a set of special lithologic profiles have been deposited in the Eocene Funing Formation. Especially, after obtaining high-yield natural gas in Well Dong 60 and Well Dong 64 of Funing Formation in Jinhu Depression, it has aroused great concern and interest in oil and gas geology. Professor Yan Qinshang from the Department of Marine Geology of Tongji University and Professor Xiang from Nanjing Institute of Geology and Paleontology cooperated with us to study the sedimentary facies and regional geological environment of Funing Formation in Jinhu Depression.
Biogenic limestone is rich in polychaetes and other fossils, which can often become rock-forming organisms, forming insect reef limestone and insect clastic limestone, thus becoming an important oil and gas reservoir rock in the basin.
According to Nanjing Institute of Geology and Paleontology, Chinese Academy of Sciences, the tube fossils of these worms belong to the secluded subclass of Polychaeta, belonging to 3 families, 6 genera and 7 species:
(1) CERATOPOGONIDAE:
(a) sempulinae of ceratera:
(I) ceratosaurus sinensis Yu et wenggen et sp. nov (new genus and new species)
Angiostrongylus fasciculata (new genus and new species).
(3) Guyer's bacteria? The genus Tetrastichus (New Species)
(b) snail:
(1) Dexiospira is a new species of right-footed in Jiangsu.
(2) Bizoon spiro
(2) Terebelidae: Golden Lake Chiroptera? (new species) Terebella? Jade and king of Jingwu, a new species
(3) Diptera insects:
Anterior gall midge. November (New Genus and Species)
Micro-curved conical tubes and spiral tubes that secrete calcium in Chironomidae: Insects and Diptera secrete mucus-bound particles, oolites, crustaceans and terrigenous sand. Among them, Chironomidae is the most widely distributed and abundant in this area, which can form reefs.
Polychaete worms are typical marine animals, which are mostly found in marine strata or brackish river mouth sediments, and should belong to brackish water or brackish water, marine or transitional marine organisms.
In addition to the tube fossils of polychaetes, algae can also be seen. It is an important rock-forming organism for building carbonate rocks, and its species are mainly low-grade cyanobacteria. According to Zhu Haoran's research, Cladosporium in China often represents the marine environment, which, like Insecta, should be presumed to be saline water environment. At the same time, there are fish fossils (new species) of Perciformes, Polypodiaceae and Hongze Dongting fragrant fish. 1 1 month is in the fourth member shale of Funing Formation.
According to the above fossil species and the indicator minerals of glauconite in Funing Formation found in the core of Dong 64 well, it is preliminarily considered that the Funing Formation in Jinhu Depression belongs to shallow sea facies or estuary facies with land-sea transition.
In Paleogene lithofacies palaeogeography, transgression deposits appeared in Subei Basin. Need to know how the lake basin communicates with the sea? Where is the sea? What is the regional background of northern Jiangsu and its surrounding areas? Let's get a general understanding of the sedimentation of several eastern basins adjacent to northern Jiangsu:
Jianghan Basin: According to Liu's report, foraminifera in Jianghan Salt Lake are mainly five-eared worms, three-eared worms and a few bottle worms, and barnyard grass can be seen, with boron content of 0.0/kloc-0.8% ~ 0.035%, and the deposition process may be affected by seawater.
Bohai Bay Basin: According to the report of Tang Xianghua, Institute of Geology, Petroleum Exploration and Development Research Institute, calcareous nannofossils, such as Reticulofenestra sp. Coccolith. There is a crown cycle in the middle and lower part of the third member of Shahejie Formation in the northern part of Hedong Depression. Species.
The calcareous nannofossil in the lower part of Shahejie Formation 1 member in the western depression of Liaohe River is Retjculofenestra sp., belonging to cocci. And Cyclocococithitina sp.
Calcareous nannofossils have been found in marine strata from the middle and late Eocene to Oligocene on both sides of the Atlantic Ocean, Narchik in the northwest Caucasus, central and northern Germany and Alabama, USA.
It can be seen that the fossils of the Paleogene Funing Formation in northern Jiangsu are closely related to the transgression of several Paleogene basins in the whole eastern region. During this period, it was in a transitional environment between land and sea, sometimes connected with the sea and sometimes closed. Besides calcareous nannofossils, there are marine fish, algae and foraminifera in Bohai Bay Basin, and the reliability of the data is beyond doubt.
The researchers believe that it is appropriate to generalize the sedimentary facies of Funing Formation in northern Jiangsu by the "estuary facies" of land-sea transition, because it is rich in organic matter and creates good oil-generating conditions, so it has a very important position in oil and gas geology.