Sinopec shale gas ultra-long horizontal well drilling set two records

On October 27, the Jiaojiao 18-S12HF well in the Fuling shale gas field of Sinopec Jianghan Oilfield was successfully completed to a depth of 7,161 meters
.
Among them, the horizontal section is 4286 meters long, and the horizontal section is 4225 meters "one way drilling", setting two records
for the length of the horizontal section of shale gas wells and the length of the "one trip drilling" advance of the horizontal section in one fell swoop.

Photo: Construction of Jiaopan No.
18 drilling platform in Sinopec's Fuling shale gas field

Shale gas is an unconventional gas reservoir, also known as an "artificial gas reservoir", and the shale needs to be crushed to get the gas out
during mining.
Horizontal well technology is particularly critical
in this process.
"Just like drinking soy milk, conventional gas reservoir development only needs to insert a straw to drink soy milk, while shale gas development needs to continue to extend the straw laterally after inserting the straw, and then crush the shale through fracturing to form a channel, so that the gas can continue to come out
.
" Relevant technicians of Fuling shale gas field said that ultra-long horizontal wells refer to horizontal wells with a horizontal section length of more than 3,000 meters, which are limited by many technical problems such as difficulty in carrying rock cuttings, complex force on drilling tools, and high risk of collapse of the well wall, which is difficult to achieve in mountain shale gas drilling, and has always been a difficulty in the efficient development of
domestic shale gas.
As a national shale gas demonstration area, Fuling shale gas field has made every effort to tackle shale gas ultra-long horizontal well drilling technology, and took the lead in realizing the drilling of ultra-long horizontal wells above 3,000 meters of shale gas in China
on February 28, 2018.
At present, Sinopec's horizontal well technology can drill more than 4 kilometers
in a directional direction within an error range of less than 5 meters.

According to reports, the thickness of shale gas layers underground generally ranges from tens of meters to hundreds of meters, and horizontal drilling must indicate where to hit to ensure accurate
targeting.
The Fuling shale gas field development team independently developed a three-dimensional visual comprehensive geological guidance technology, which equipped the drill bit with "eyes", so that it can use the stored massive geological data to adjust the drill bit's trajectory at any time, so that the drill bit can achieve "straight line acceleration" and "drift and turn" in the underground palace, and travel through the high-quality reservoir like "pancake" at high speed like a "snake"
.
At the same time, they have innovated and developed technologies such as key equipment and tools for ultra-long horizontal wells, friction reduction and drag reduction of ultra-long horizontal wells, and dynamic optimization of drilling parameters of ultra-long horizontal wells, realizing a major leap
from "unable to hit" to "playing fast and accurately".
At present, the average drilling cycle of Fuling shale gas has dropped from more than 90 days to more than 40 days, the shortest drilling cycle is only 25.
58 days, and the drilling rate of superior reservoirs has reached more than
96%.

Pictured: Employees of the Jiaopan 18 drilling platform in Sinopec's Fuling shale gas field inspect tubing

With the deepening of the development of the Fuling shale gas field, the underground well network has become more and more dense, and most of the new wells deployed are located in the "downtown area", and the closest wells are only 30 meters
away.
The development team has innovatively developed intelligent anti-collision obstacle technology
.
The application of this technology can realize real-time dynamic monitoring and three-dimensional visualization, scan the position of the "adjacent well" at any time like "radar", so that the drill bit can maintain a safe distance and high-speed driving status, successfully cross the "danger zone" and reach the destination
smoothly.
Relying on this technical support, Jiaopan No.
12 platform successively deployed 18 gas wells, reducing the land acquisition area and realizing efficient development
.

The team also developed long-level fracturing technology to help achieve high yields
.
They deepened the research on the physical properties and rock mechanics of the stratum reservoir, strengthened the post-fracturing assessment and fracture diagnosis, put into use the self-developed 5000 all-electric drive and high-power fracturing skid, and widely applied new technologies such as "multi-stage multi-cluster + temporary blocking steering + high-intensity continuous sanding" to continuously enhance the effect of formation transformation, "crush" the formation to more fragmentation, form an escape channel extending in all directions, and let shale gas continue to be produced
.
At present, there are 180 gas wells in the Fuling shale gas field with a cumulative gas production of more than 100 million cubic meters
.

Figure: Schematic diagram of the horizontal segment

It is reported that since the Fuling shale gas field was put into development and construction, it has innovated the theory of shale gas exploration and development, formed six core technologies, realized the efficient development of shallow gas reservoirs of 3500 meters and the effective development of gas reservoirs of 3500 to 4000 meters, pioneered the three-dimensional development technology of shale gas in China, and the recovery rate of the three-dimensional development zone has reached the international advanced level
.
Up to now, the cumulative proven reserves are nearly 900 billion cubic meters, the cumulative production capacity is 15 billion cubic meters, and the cumulative output has exceeded 47 billion cubic meters, sending clean energy to more than 70 large and medium-sized cities in 6 provinces and 2 cities along the Yangtze River Economic Belt, benefiting thousands of enterprises and nearly 200 million residents
.