彩南油田水平井联合直井整体加密井网优化研究

A study on the optimization of overall infill drilling program by a combination of horizontal and vertical wells in Cainan oil field.

准噶尔盆地彩南油田彩１０井区三工河组油藏目前的基础井网偏稀，单井控制储量偏大，造成水驱控制储量程度偏低，水驱效果较差，油田产量递减。应用数值模拟和运筹学最优化技术，充分考虑地应力、井间干扰、经济因素和井网井距，对彩南油田水平井联合直井加密的综合经济效益进行对比研究，寻找最少投资下可最大幅度增产的水平段长度和加密的最优井距。根据研究结果认为，底水砂岩油藏水平井加密具有投资少、抑制底水锥进和产量高的优势，可提高采油速度０．７％，提高采收率４．５％，增加可采储量２４．２６×１０４ｔ。

Sangonghe Formation reservoir in Well Cai 10 area, Cainan oil field, Junggar basin is developed by a rather large spaced basic well pattern, thus the reserves controlled by a single well is rather large, but the reserves controlled by water flooding is very low, resulting in an poor water flooding and a declining oil production rate. Comprehensive economic profit of an infill drilling program by a combination of horizontal and vertical wells is comparatively studied by means of numerical simulation and operational optimization technique, taking geo stress, interwell interference, economic factors and well spacing as well as well density into sufficient consideration to find out the length of horizontal wells and optimized well spacing to yield maximum increase in production rate under least investment. Infill drilling by horizontal wells have the superiority of less investment, bottom water coning inhibition and high production in developing a bottom water driven sandstone oil reservoir: ①annual oil production percentage of OOIP will increase by 0.7%; ②recovery factor will increase by 4.5%; and ③recoverable reserves will increase 24.26×10 4t. The mathematical model established for an optimization design of well density can be used for locating well sites both in oil fields ready to be developed or to those developed already.