多缝压裂新技术研究与试验

Study and test on the new technology of multi-fracture fracturing

唐梅荣 赵振峰 李宪文 赵文

TANG Meirong ZHAO Zhenfeng LI Xianwen ZHAO Wen

长庆油田公司油气工艺研究院，陕西西安　710021

Changqing Oilfield Company Oil &

受到注采井网和压裂工艺双重限制，单纯增加缝长来提高超低渗透油藏产量效果已不明显，为此提出了定向射孔多缝压裂技术思路，通过定向射孔诱导定向起裂，迫使初始裂缝转向，最终形成相互独立的多缝，进一步提高油层横向动用程度，扩大泄油面积。通过物模研究，认识到射孔方位和水平应力差是影响多缝形成的关键因素，在此认识上，优化了压裂工艺。华庆地区现场试验2口井，通过净压力拟合和微地震裂缝监测等手段分析，初步证实层内形成了独立多缝。投产初期，试验井相比邻井井均日增油0.91 t（增幅约26％），实践证明通过多缝压裂提高泄油面积可以达到增产的目的。

Due to the restriction of flooding patterns and fracturing technologies, it is not distinct to increase the output of super-low permeability reservoir in Changqing Oilfield only by increasing fracture length. Enlightened by the fact that the directional perforating can reduce the pressure of rock fracturing, the new technology of directional perforating and multi-fracture fracturing is firstly brought forward. This technology improves horizontal productive degree of oil layer and enlarges the drainage area through directionally perforating to induce oriented extension, forcing initial fracturing to change, and finally forming independent multi-fracturing. Through the study of entity model, it is recognized that perforating azimuth and horizontal stress difference are the key factors that affect the formation of multi fractures. Based on this recognition, fracturing technology is optimized. Two wells were tested on the spot in Huaqing area. It is approved initially that independent multi fractures is formed inside layers through the analysis on net pressure matching and microseismic frac mapping. At the initial production stage, the average daily oil production of trial wells increases by 0.91 tons (growing rate is about 26%) compared with the adjacent wells. This practice proves that production can be increased by increasing drainage area through multi-fracture fracturing.