Abstract:

Shale oil in the fourth member of Shahejie Formation in Dongying Depression has advantages such as large resource, thick reservoir, high formation pressure coefficient, and developed natural fractures and micro-fractures. However, that it is affected by unfavorable factors such as burial depth, development of faults and high formation temperature leads to high fracturing cost, rapid decline and poor economic benefit. In order to overcome the problems such as the narrow pressure fracture width and the difficulties during sand addition in the fracturing of the continental shale oil reservoir by the conventional fracturing technology, and promote the production of shale oil in the fourth member of Shahejie Formation, the on-site tests are conducted in Well-G17-X10 of Niuzhuang Sag with the performance of the self-suspension and self-reducing resistance properties of the self-suspension proppant and combined with complex network fracturing technology. The results show that compared with the adjacent well, Well-GX26, Well-G17-X10 not only has lower fracturing difficulty, double sand ratio and less liquid reduced by 30 %, but also has 520 days of self-injection production period, which is 436 % of that of Well-GX26, and 2 482 t of oil production period, which is 344 % of 722 t of Well-GX26. This achievement verifies the unique advantages of self-suspension proppant in improving effective suspension of fractures and increasing seepage volume of oil wells. It not only successfully explores a new fracturing stimulation technology, but also broadens the technical idea of shale oil efficient production.

Key words: shale oil, self-suspension proppant, increase production, Niuzhuang Sag, the fourth member of Shahejie Formation