200 questions on drilling knowledge - Geology
2024-05-22 10:00200 questions on drilling knowledge - Geology
1. What are the three major categories of rocks according to their origin?
Answer: 1. Igneous rock is also called magmatic rock 2. Sedimentary rock 3. Metamorphic rock.
2. Please name three types of igneous rocks and describe their characteristics?
Answer: Granite, basalt, and syenite are all igneous rocks. They are characterized by being unstratified, massive, and generally very dense and hard.
3． What minerals are common sedimentary rocks made of?
Answer: It is mainly composed of quartz, feldspar, mica, calcite, clay and other minerals.
4. How are sedimentary rocks formed? What are the characteristics?
Answer: Because igneous rocks, metamorphic rocks are exposed to wind and rain. Affected by factors such as temperature changes, biological effects, and water dissolution, the debris is eroded and broken, forming clastic materials, dissolved materials, and residual materials. After being transported by flowing water, wind, glaciers, oceans, etc., they leave the original place and are deposited under appropriate conditions. Down, after compaction and consolidation, sedimentary rocks are formed, which are characterized by bedding and mostly contain animal and plant fossils.
5. Name the five main sedimentary rocks?
Answer: 1. Mudstone and shale 2. Sandstone 3. Conglomerate 4. Limestone 5. Dolomite
6. Give an example of how sedimentary rocks are formed?
Answer: Sedimentary rocks or igneous rocks undergo metamorphism under the physical and chemical factors inside the earth's crust, changing their original composition and structure to form metamorphic rocks. For example, limestone turned into marble, and granite turned into gneiss.
7. In which rock formations are oil and natural gas primarily stored?
Answer: Mainly in sandstone layers with trap conditions and limestone layers with well-developed fracture caves.
8. What type of rock is a good seal for oil and gas traps?
Answer: Mudstone, shale and thick gypsum rock.
9. How are oil and natural gas formed?
Answer: Mainly organic sediments in shallow seas, bays, inland lakes and other places are quickly covered by other new sediments, so that the organic matter is preserved without being oxidized. As the sediments continue to thicken, the pressure and temperature continue to increase. With the addition of bacterial action, these organic substances become oil and natural gas after complex physical and chemical changes.
10． What are the two broad types of oil and gas reservoirs?
Answer: Structural oil and gas reservoirs and stratigraphic oil and gas reservoirs.
11. Please write down the names of seven rocks with higher hardness?
Answer: Marble, gravel, granite, iron ore, chert, basalt, dolomite.
12． Write the name of the most drillable rock?
Answer: Flowing sandstone, clay rock, salt rock layer, gypsum rock, and coal seam.
13． Which five types of rocks cause the most wear and tear on drill bits and drilling tools?
Answer: Conglomerate, chert, natural copper, iron ore layer, quartz sandstone.
14． Name the five rock formations most likely to cause drilling?
Answer: Conglomerate layer, granite interlayer, chert interlayer, weathering crust, basalt interlayer.
15. Name the five rock formations most susceptible to collapse?
Answer: Quicksandstone, gravel layer, coal layer, salt rock layer, mudstone layer.
16. Name the three rock formations most prone to leakage?
Answer: Weathering crust is obtained from coal seams, large-grained gravel layers, and ancient buried hills.
17． In the Zhongyuan Oilfield, in which well section do salt rock and salt-gypsum layers usually appear?
Answer: It mainly occurs in the Sha1 and Sha3 members of the Shahejie Formation. The Sha3 member is usually divided into two parts. The upper part appears in Sha23 (Wenjiu Salt) and the lower part appears in Sha43 (Wen23 Salt).
18. Highly productive oil and gas formations are typically found in what type of rock?
Answer: Sandstone layers and ancient underlying layers with good sealing conditions.
19. What are the characteristics of ancient latent oil and gas reservoirs?
Answer: Because the rock fractures in the ancient underlying layer are well developed and the caves are large, the oil and gas reservoirs in the ancient underlying layer are usually low-pressure and highly productive.
20. Which geological layers are generally encountered when drilling in Zhongyuan Oilfield? What layer is usually drilled to?
Answer: Generally, you will encounter the Pingyuan Formation, Minghuazhen Formation, Guantao Formation, Dongming Formation and Shahejie Formation. Referred to as Ping, Ming, Guan, Dong, Sha. The Shahe Street component is divided into four sections, namely Shahe 1st Section, Shahe 2nd Section, Shahe 3rd Section and Shahe 4th Section. Because the Sha3 section is thicker, the Sha3 section can be divided into four layers, namely Sha13, Sha23, Sha33 and Sha43. Sometimes exploratory wells have to be drilled to reach the Kongdian Formation, Carboniferous and Ordovician systems. In most cases, drilling reaches the Shahejie Formation and is completed.
21. In the Tarim Basin, which groups of geological layers are generally encountered when drilling? What layer is usually drilled to?
Answer: Generally, drilling will encounter the Kuqa Formation, Kangcun Formation, Jidik Formation, Suwei Formation, Cretaceous, Jurassic, Triassic, Carboniferous Permian, Carboniferous and Ordovician. Abbreviated as Ku, Kang, Ji, Su, Bai, Zhi, San, Er, Shi and Ao. Sometimes in some exploratory wells, before drilling into the Ordovician System, the Devonian System and the Silurian System may be encountered, and then the drilling is completed.
22. Gravel layers are sometimes encountered during drilling. Which layer does they mainly appear in the Central Plains? What is the display on the drill floor when drilling into a gravel layer?
Answer: It mainly appears in the Guantao Formation. Sometimes small-grained gravel layers also appear in the upper part of the Dongying Formation. When drilling into a gravel layer, a skipping or lagging display will appear on the drill floor.
23. The weathering crust that people often talk about is located at the top of which geological layer? What complications typically arise when drilling into this layer?
Answer: Located at the top of the Ordovician strata. The main complications when drilling into weathering crust are lost circulation, drill skipping or poor drilling.
24. What are the five main methods of logging?
Answer: 1. Sand sample logging, also known as cuttings logging; 2. Core logging, also known as core logging; 3. Drilling logging; 4. Drilling fluid logging; 5. Gas logging.
25. What are the six main contents of geophysical well logging?
Answer: 1. Apparent resistivity 2. Natural potential 3. Neutron gamma 4. Gas measurement 5. Natural gamma 6. Well diameter