Editor's note: Jilin Oilfield is a typical "three low" oilfield with low permeability, low abundance and low output, and with the increase of production life, the contradiction in the development of old oil areas is becoming increasingly prominent. In the face of the development dilemma, Jilin Oilfield relies on technological innovation to open up a new path for development
As of December 25, Jilin Oilfield's production this year has completed 98% of the annual plan. At the same time, the workload of drilling, fracturing, production and other main bodies has been advanced ahead of schedule, and the production situation continues to improve.
Jilin Oilfield is a typical "three low" oilfield with low permeability, low abundance and low output, and with the increase of production life, the development has entered the middle and late stages, and the contradictions such as low production of multiple wells and ineffective water circulation are becoming increasingly prominent. In the face of development difficulties, Jilin Oilfield has opened up a new path of sustainable development by actively promoting fine water injection, technological innovation and low-carbon transformation.
Fine-do: "Water Article" Dig deep into the remaining oil
For old oil fields, water flooding is still the most economical way to develop. With the increasing water flooding time, the old development area of Jilin Oilfield is facing the problems of increasing water cut of oil wells and low well production. Slowing down the aging rate of old areas is a difficult point that must be solved to achieve sustainable development of Jilin Oilfield.
In the Buyeo oil production plant, solving the "water problem" through fine water injection adjustment is one of the effective methods to stabilize production in recent years. This oil production plant takes water quality improvement, wellbore control, water flooding, and water cut control as the main starting points, strengthens the dynamic analysis of the well group, implements oil well transfer, injection-production adjustment, etc., timely replenishes formation energy, improves oilfield oil recovery, slows down the rise rate of water cut, and further improves the injection-production correspondence and balanced longitudinal water absorption.
Among the 11 oil-producing blocks of the Fuyu Oil Production Plant, Dongtan Block 93 has a high water cut, and the total daily production of more than 200 oil wells has dropped to 65 tons in 2017. Through in-depth analysis of the formation conditions, the technicians found that the oil well in this block was sensitive to water injection, and the permeability of water flow was uneven between different formations. Accordingly, the technicians adjusted the water flooding scheme of Dongtan 93 block to intermittent water injection and interstratum differential water injection. The modified scheme not only ensures that the water content of the oil well does not rise, but also increases the driving force of a specific location in the underground. The test results are obvious, and the daily production of Dongtan 93 block has been stable at about 80 tons in recent years without adding new wells.
Jilin Oilfield adheres to the problem-oriented, does a good job in the fine management of water wells, deepens the research on process geology, improves the process supporting technology, and coordinates the promotion of fine water injection. For under-injection wells with blockage, poor formation water absorption and high water injection pressure near the well, mature injection processes such as active agent squeezing, acidification injection, and fracturing injection are vigorously promoted to improve the water injection effect.
Innovate the development model to improve efficiency and efficiency
The sustainable development of the old area cannot simply rely on the old methods and methods, and Jilin Oilfield has opened up a new development path by strengthening the innovation of intelligent construction and development mode to improve efficiency and increase production.
At the Fuyu Oil Production Plant's oil-water treatment center, adjusting the level of the oil-gas two-phase separator used to be a very troublesome job for front-line employees. Due to the instability of the amount of liquid from the oil wells in the jurisdiction, the liquid level height in the two-phase separator is prone to large fluctuations. "If the liquid level is too high, ** will enter the gas line;If the liquid level is too low, the gas will enter the ** treatment unit. Both cases are production accidents, and once they occur, they will directly affect the output. Gao Yanqiu, a technician at the central station, explained. In June 2023, with the start of trial operation of the IoT transformation project of the central station, relying on the newly installed drive unit and a set of computer control system, the outlet valve of the two-phase separator was automatically adjusted according to the liquid level.
In addition to the innovation of management methods, Jilin Oilfield has also innovated and explored a new model of intensive construction and production of low-permeability oilfields. In order to achieve the benefit of construction and production, through the construction of the "large well cluster" platform, the development contradiction of multiple wells and low production is well solved. At the beginning of 2022, the No. 16 "large well cluster" platform of Jilin Oilfield Xinli Oil Production Plant was put into operation. Different from the traditional form of scattered distribution of single wells, the platform adopts the interdisciplinary interactive design of geology-engineering integration, the intensive layout of large well clusters, and further improves the production and operation efficiency by reconstructing the underground well pattern, adopting a series of new technologies, new processes and new equipment such as direct drive hydraulic oil production unit, integrated heating furnace, photovoltaic energy power supply, etc., and the investment in the construction of one million tons of production capacity has been reduced by 20%.
At present, most of the new wells in Jilin Oilfield have adopted the platform mode. Zhang Chengming, executive deputy director of Xinli Oil Production Plant, said, "This method can realize centralized well drilling, centralized underground pipeline setting and centralized management." In addition, according to the characteristics of low production of a single well, the No. 16 platform uses the hydraulic direct-drive pumping unit independently developed by Jilin Oilfield to replace the traditional pumping unit. The new pumping unit is light in weight, occupies a small area, and the stroke and stroke can be adjusted steplessly, which is highly efficient and energy-saving, and saves 25% of energy consumption compared with the traditional pumping unit.
Build a new multi-energy complementary structure to promote integrated development
In recent years, Jilin Oilfield has actively implemented the low-carbon strategy, built a new business structure with high-quality multi-energy complementarity, and promoted the integrated development of oil and gas development and new energy.
Block 20 of Xinmu Oil Production Plant is the key block for the production capacity construction of Jilin Oilfield this year. In order to improve the efficiency creation capacity and stable production level of the block, Jilin Oilfield innovated the concept of secondary development of old oilfields, and established a new model of low-grade resource benefit development and new energy integration development by building an upgraded version of "large-scale platform intensive construction and production" and a demonstration project for green power isolated grid operation.
In the process of secondary development and potential mining, Jilin Oilfield found that the block has high controlled reserves and low formation energy, and the potential space is very large. According to the capacity construction plan, 70 wells are planned in the first round of the Miao 20 block. In order to rejuvenate this old area, Jilin Oilfield has innovated in many aspects such as construction and production concept, development mode, operation management, etc., and formed a new model of "large pumping + new energy + large platform + digital integration" of low-permeability reservoir global cycle injection and production production. After the completion of the block, the energy consumption will be provided by green electricity and self-produced associated gas, and the annual output is expected to increase by 67 times, 8 times higher recovery8 percentage points.
Compared with water flooding, carbon dioxide has stronger energy after being injected into the ground, and can also form miscibility with specific conditions, which is an effective medium for "squeezing" oil in the later stage of low permeability oilfields. The natural gas produced from the Changling gas field in Jilin Oilfield is accompanied by a concentration of about 23% carbon dioxide, which provides the basic conditions for carbon dioxide flooding. At present, there are 69 gas injection wells and 270 oil wells in Jilin Oilfield that have implemented carbon dioxide flooding. Early tests have shown that under the best conditions, compared to water injection, the oil recovery factor of the gas injection development can be doubled over the life cycle of the well, which is equivalent to rebuilding a reservoir of the same size.
Jilin Oilfield has carried out the whole life cycle test of carbon dioxide flooding and buried small well spacing in the main layer in the Hei 79 North Block, which has been continuously injected for more than 10 years, and has gone through three stages: energy replenishment, local miscibility, and comprehensive effect. The recovery rate of the small well from the core evaluation area is increased by more than 25%, and the final recovery rate reaches 561%。The enhanced oil recovery effect is equivalent to the development of a new water-flooded oil field of the same size.
* |China Petroleum News.
Reporter |Wang Shanshan.
Correspondents |Peacefulness.
Edit |Yan Chuting.
Editor-in-charge |Hua Jinyan.