岩屑自然伽马能谱和元素录井技术在双鱼石构造栖霞组固井卡层中的应用  

Application of cuttings natural gamma spectroscopy and element logging techniquesto determining cementing horizon of Qixia Formation in Shuangyushi structure

作　　者：杨廷红 曾令奇 龚勋 何成贵 张雷 罗谋兵 魏建强 YANG Tinghong;ZENG Lingqi;GONG Xun;HE Chenggui;ZHANG Lei;LUO Moubing;WEI Jianqiang(Research Institute of Geologic Exploration and Development,CNPC Chuanqing Drilling Engineering Company Limited,Chengdu,Sichuan 610051,China)

机构地区：[1]中国石油川庆钻探工程有限公司地质勘探开发研究院

出　　处：《录井工程》2020年第1期28-34,共7页Mud Logging Engineering

摘　　要：川西北地区双鱼石构造因钻井新技术的应用和复杂的地质构造,致使岩性识别和层位判断变得十分困难,同时传统录井分层卡层技术的局限和钻井工程对栖霞组固井的严格要求,这些都对栖霞组固井层位的准确卡取带来极大挑战。为解决这些不利因素带来的困难,该区块普遍利用岩屑自然伽马能谱和元素录井技术选取岩屑自然伽马总量及元素Ca、Mg、Si、Sr、Ba、K、Th等参数,对茅口组岩性的微观特征和地层化学特征进行识别,利用标识出的特征层对茅口组进行跟踪对比,其中第Ⅲ特征层岩屑自然伽马为“箱状”中高值;造岩元素Ca呈“箱状”高值,元素Si虽明显高值,但具“拖尾”趋势,表征沉积物成熟度的K/Th比值大于0.15,呈明显的高值。该层底即茅口组底,以岩屑自然伽马和K/Th比值下降、元素Si“拖尾”为特征与下伏栖霞组分层,为栖霞组固井卡层提供可靠的技术手段,取得了双鱼石构造二叠系栖霞组固井卡层准确率100%的良好效果。Due to the application of new drilling techniques and complex geologic structures in Shuangyushi structure in the northwestern Sichuan, it is difficult to identify lithology and determine the horizon. Meanwhile, the limitation of horizon division and determination in traditional mud logging and the strict requirements of drilling engineering on the cementing of Qixia Formation have brought great challenges to the accurate determination of cementing horizon of Qixia Formation. In order to solve the difficulties caused by these unfavorable factors, cuttings natural gamma spectroscopy and element logging techniques were widely used in this block to select the total natural gamma of cuttings, elements of Ca, Mg, Si, Sr, Ba, K, Th and other parameters to identify lithology microscopic features and formation chemical characteristics of Maokou Formation. The identified diagnostic horizons were used to track and compare the Maokou Formation, among which the cuttings natural gamma of the 3rd diagnostic horizon was box-like medium and high values, the rock-forming element Ca showed a box-like high value, while the element Si was obviously high value, but it had a trailing trend, and K/Th characterizing the maturity of the sediment was greater than 0.15, showing an obviously high value. The bottom of this layer is the bottom of Maokou Formation, it is stratified with the underlying Qixia Formation with characteristics of the decrease of cuttings gamma and K/Th, and the trailing of element Si. It provides reliable technical means for determining cementing horizon of Qixia Formation, and achieves a good effect of 100% accuracy for determining cementing horizon of Permian Qixia Formation in Shuangyushi structure.

关 键 词：川西北地区 自然伽马能谱 元素录井 双鱼石构造 茅口组 特征层 栖霞组 固井卡层 

分 类 号：TE132.1[石油与天然气工程—油气勘探]