Trachyte

Classification：Igneous Rock

Trachyte is a neutral volcanic eruption rock. The composition is equivalent to the Yu Zheng long rock. The matrix is cryptocrystalline, was light gray, pale yellow or pink
Red, with pores or porous slag structures. Porphyritic, rough shape, spherical and massive, rhyotaxitic, vesicular structure. They are usually divided into two types: calc alkaline Trachyte and alkaline Trachyte. Calc alkaline Trachyte is mainly composed of alkaline feldspar, plagioclase and a small amount of dark minerals. Alkaline feldspar with feldspar
It is mainly composed of anorthite. The dark minerals are mainly biotite, containing a small amount of amphibole and pyroxene. The basic Trachyte is characterized by some alkaline dark minerals, sometimes containing a small amount of feldspar minerals, and the light colored minerals are mainly alkaline feldspar (permeable feldspar, ortho feldspar, askew feldspar, etc.) with little plagioclase. It can also be further divided into potassium Trachyte with K-feldspar and sodium Trachyte, which is mainly composed of albite. According to the feldspar contained, Trachyte is basically divided into:
Potassium Trachyte mainly contains alkaline feldspar, and sodium Trachyte mainly contains albite and anaspore.

The cause of formation:
According to the origin of Trachyte, one view is that coarse magma is derived magma and is mainly related to magmatic assimilation. Another view is the product of the differentiation of alkaline basaltic magma. There are two evolutionary trends of differentiation. The first is the direction of alkalinity increasing, that is alkaline basalt, coarse anite, Trachyte and rock, and two is the direction of acidity increasing, that is alkaline basalt, Trachyte, alkaline rhyolite. Journal of related literature the Journal of special oil and gas reservoir geotectonics, petrology, petrology, petrology, petrology, petrology, petrology, petrology, geology, petroleum, natural gas, volcanic geology and mineral geology.

Information:
5 years before the successful exploration of the Trachyte oil and gas pools in Liaohe Oilfield, the world authority magazine, the American Petroleum Geological Society Forum, published the picture of the Trachyte core of Liaohe Oilfield on the cover, and called it "an attractive exploration field". Now, Liaohe people have really realized the "tempting" of Trachyte exploration.
By the end of September, 33 wells wells Nissan Trachyte test of crude oil has maintained a level of 20 tons in the month. In the past few months, the well 51 and 35 wells also worked well in Trachyte well, and Nissan crude oil and natural gas have been maintained at 58 tons and 25 thousand and 600 cubic meters respectively. The 3 exploratory wells initially control 6.42 square kilometers of oil area. This year, we expect to control more than ten million tons of petroleum geological reserves. It also makes the exploration of Trachyte reservoir in eastern sag of Liaohe basin showing a continuous trend.
Experts say that the success of Trachyte exploration in Liaohe Oilfield has filled the gap in the field, indicating that the Trachyte exploration and matching technology of CNPC has reached the international advanced level.
Trachyte is a kind of volcanic rock. In the early development of Liaohe Oilfield, high production oil and gas flow was obtained in the volcanic well section. However, because of its unclear reservoir performance, oil and gas mechanism and so on at that time, the technical means were limited, so it was not regarded as the main exploration target. With the continuous improvement of the exploration degree in the Liaohe Oilfield, the complex and concealed exploration targets, such as Trachyte, have gradually attracted the attention of the oil field operators and began to march into this field. From 2000 to 2004, Liaohe Oilfield found 31 million 940 thousand tons of oil and gas reserves in the Trachyte oil and gas reservoirs in the eastern depression, accounting for 60% of the total proven oil reserves in the eastern depression, and a good prospect for the exploration of Trachyte oil and gas reservoirs.
The main mineral of opaque glaze Trachyte mainly composed of Trachyte is trachyte feldspar, and feldspar contains lots of new K-feldspar and albite system plagioclase. Its chemical composition range: 54.36 54.485 10:, o.3OTIO:, 20.14 20.42A1203,4.80 1 4.91Fe:03,3.61 3.65CaO, 1.42 1.61MgO, 6.18 6.22Na20,1.22 4.18K20,4.12 sunburn. The melting temperature is 1120 1 1 140oC. The glaze made from the Trachyte, the main component of the Soviet German Gang, is bright yellow, with the best ratio of opacification glaze of 84%Trachyte, 12% borax and 4% potassium carbonate. In the 1300 "C fused frit, milling outside 2% bentonite into glaze. The chemical composition of the glaze (%): 51.295102,19.94A120. 4.34Fc203,3.21CaO, 1.34MgO, 8.6NaZO, 5.16K20,0.36T 10. 5.32B20. Glaze is opaque before 950 "C". The opaque phase is ZMgO Tio. According to the study, in the glaze made of aluminum, magnesium and Qinhua igneous rocks, there are usually diopside CaO, Mgo, 25102 crystals with a size smaller than 1 microns.
The development characteristics, problems and Countermeasures of the yellow sand Tuo Trachyte reservoir, the yellow sand Tuo Trachyte reservoir occupies an important position in the domestic volcanic reservoir because of its unique lithology and large reserves. Different from the general weathered crust type volcanic reservoir, the reservoir is formed by tectonic stress, deep dissolution and other physical and chemical effects, and is a reservoir with the characteristics of fracture and pore double medium. Because of the poor core representation, the overall conformity rate of the conventional static description method in the reservoir is not high: the average permeability of the core analysis is only 0.994 x 10-3 m2, but the average well test permeability is 19.67 * 10-3 Mu m2, and the gap is nearly 20 times. Therefore, this paper mainly uses the dynamic data of oil and water well production and reservoir dynamic monitoring data, summarizes the characteristics and laws of reservoir development, tries to recognize the reservoir geology from the macro aspect, and finds out the existing problems in the reservoir development on this basis, and then points out the direction of the next step of production and development.
The main development characteristics of the reservoir are as follows: high oil well initial production, high productivity, high productivity, fast flooding in oil production, rapid flooding after water production, rapid flooding after oil well adjustment, and declining of production capacity of the well affected by old wells, and water flooding, but the effect of flooding is not serious, but the oil increase effect is not serious. It is not obvious.
Through the above development characteristics, the macro re recognition of reservoir geological formation is that the area is stored in three types of reservoirs (high and high yield flooding, crack - pore middle middle and slow submergence type, micro slit hole production long term water type) in the area, and the three eruption periods in the reservoir are not obviously stratified during the development of the reservoir; The main faults are not obviously sealed. The distribution of original oil and water is mainly controlled by structural position, but the oil-water transition zone is greatly influenced by capillary force.
At the end of this paper, the main development direction is pointed out in view of the strong heterogeneity of the reservoir and the difficulty of stabilizing the oil and water in high water cut stage.