Abstract
Abstract This paper introduces a steam-foam drive profile modification technology for heavy oil development in Block Qi40 based on an in-depth study of the characteristics of heavy oil reservoir and cross flow characteristics of injected steam in Block Qi40 of Liaohe Oilfield. The performance evaluation was carried out indoors for foaming agents. Influencing factors affecting profile modification and foam injection mode selection are studied. The results show that the CX-4 foaming agent system has excellent foaming properties and foam stability at 300°C. The plugging pressure difference of core can be increased by more than 15 times at 240°C. When a 0.5 PV foaming agent system is injected, the oil displacement efficiency can reach more than 68%. The optimal concentration of the foaming agent is 0.5% and the change of resistance factor is the largest in the range of oil saturation between 15 and 20%. Foam has better plugging ability in high permeability and large pores. Furthermore, after field application effect analysis, it confirms that the steam-foam profile modification technology has an obvious effect on enhancing oil recovery.
Highlights
This paper introduces a steam-foam drive profile modification technology for heavy oil development in Block Qi40 based on an in-depth study of the characteristics of heavy oil reservoir and cross flow characteristics of injected steam in Block Qi40 of Liaohe Oilfield
According to the characteristics of the heavy oil reservoirs in Block Qi40 of Liaohe Oilfield, by using the oil sand samples, dewatered oil, and simulated formation water from the steam drive pilot test zone in Block Qi40, the main performance evaluation and selection were carried out indoors for the four foam agents (CX-1, CX-2, CX-3, CX-4), whose main component is α-olefin sulfonate anionic surfactant with an effective concentration of 20%
The increment in steam injection pressure indicates that the foam profile modification decreased the mobility of steam and increased plugging pressure difference, achieving the purpose of plugging steam channeling paths, adjusting steam entry profile, and improving displacement and sweep efficiency
Summary
Abstract: This paper introduces a steam-foam drive profile modification technology for heavy oil development in Block Qi40 based on an in-depth study of the characteristics of heavy oil reservoir and cross flow characteristics of injected steam in Block Qi40 of Liaohe Oilfield. Steam channeling is the most difficult technical problem during steam huff & puff and steam drive processes for heavy oil development. After many years of development, the main oil fields have entered into the multi-round huff & puff development stage, and there have been problems such as low reservoir pressure, high water content, low well yields, low recovery rates, and deteriorated physical properties, etc. Laboratory study and field practice show that steam drive development is the most effective mode of further improving heavy oil reservoir recovery rates. Foam has the ability to control the fluidity selectively, improve the displacement of injected fluid in the heterogeneous reservoir, reduce the fluid coning in high permeability reservoir, adjust the steam absorption profile of oil layer in the steam, block the channel of steam breakthrough, and improve the steam sweep coefficient and crude oil recovery [11,12,13,14]. The foam profile control technology is a more effective means to solve steam overlay and breakthrough
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have