(2) From "Lao Zhu (referring to the Jurassic) is not enough of a friend" to Qinghua Wu's breakthrough of 6 oil fields and dozens of oil production points in the Jurassic

For the sandstone "grindstone" of the Triassic Yanchang Formation, the physical properties of the Jurassic sandstone reservoirs have improved qualitatively with the sudden decrease in feldspar content and the decrease in cement RCO3. Variety. When we shouted "There is oil in every hole, but no flow in every hole" and "Three lows and one nothing", we lived in Yan'an at that time, and almost every day we learned from the Yan'an sandstone (sandstone at the bottom of the Jurassic Yan'an Formation) as the base of the tower. When I passed by the pagoda mountain, why didn't I think of exploring it as a reservoir? From now on, there are several "preconceived ideas" dominating my thoughts.

Figure 3-27 Structural outline of the western edge of the Ordos Basin

(According to Zhao Chongyuan, 1990)

①Narenhara; ②Bayinnuoergong; ③Qingeletu; ④Bayanwula-Langshan; ⑤Helan Shanxi; ⑥Helan Shandong; ⑦Taole; ??⑧Table Shandong; ⑨Banquet Well; ⑩Hui'an Fort-Shajingzi; Qinglong Mountain-Pingliang; Wei Prefecture - Anguo; Qingtongxia - Guyuan; Yantong Mountain - Yaoshan; Qingshui River; Xihua Mountain - Liupan Mountain; Longde

The Yan'an sandstone cannot be seen, which is controlled by the "source control" of oil and gas in the continental strata. "On" or the influence of "native" understanding of "oil-generating depression". For example, since it is a "source control theory", then west of Zhidan, the Jurassic oil-generating depression (basin facies) has entered the coal-bearing swamp facies area, and the oil of the Yanchang Formation cannot cross upward and enter the Jurassic. Therefore, although Sanpu saw good oil-bearing sandstone equivalent to Yan 8 in Wuqi’s first deep well, Wu Shen Well, as early as 1964, they still did not try it in the end. Six years later, in the same layer next to this well (Well Wu 1), the same Sanpu tested a high-yield well with a daily crude oil output of tens of cubic meters (Figure 3-28).

Figure 3-28 Lithofacies paleogeography map of the Middle and Lower Jurassic (J1-2y) in the Ordos Basin

Because there was no theory of coal-derived hydrocarbons at that time, coupled with the "native" and The thinking of "coal and oil cannot be produced" and "difficult to survive" defines the Jurassic oil prospecting range to the early and middle Jurassic areas east of Zhidan, south of Ansai and north of Fuxian. Within the range of Rashi lake facies or deeper lake facies. Therefore, the breakthroughs of Qing, Hua, and Wu in the battles of the 1970s were first of all the breakthroughs in the ideas of "coal and oil cannot be produced independently," and the "cybernetic theory." Today, if we paint the oil fields of the Yanchang Formation in red and the oil fields of the Yan'an Formation in blue, we will find that almost all Jurassic oil and gas fields are distributed in the "oil-generating depression" in West Africa between Jingbian-Zhidan-Zhiluo Town. within the coal-bearing swamp facies belt (Figure 3-29).

Figure 3-29 Schematic diagram of the Mesozoic oil and gas production area in the Ordos Basin

1—Tectonic unit boundary; 2—Paleozoic gas production area in the northern part of the basin; 3—T3y three-sided oil production area ; 4—Jurassic oil (gas) production area; 5—Outer Cenozoic graben

The Huashan 2 well deployed in Huachi Villa, the well location is based on the Sh-Z of the 342 seismic team I decided on the "Mountain Villa Swell" I found online. The original designed main target layer was the Triassic Yanchang Formation, but before the well depth reached the originally designed "target layer" of the Triassic Yanchang Formation, good oil sands were discovered in the Jurassic Yan'an Formation. There are two different opinions on whether to continue drilling the extension group as designed, or to stop drilling immediately to test the oil in the Yan'an group. According to the requirements of the situation, with the support of Comrade Chen Keren, the leader of the geological team at that time, drilling was completed ahead of schedule on July 21, 1970. On August 28 of the same year, the first Yan'an formation in Longdong with a daily output of 30.3m3 was tested. The flow of oil promoted the pace of the Changqing Battle in Longdong.