某煤矿井下穿层孔保直钻进技术措施

为了达到瓦斯抽采穿层孔保直定向钻进的目的,根据钻探工程地质条件,针对矿方采用的钻具,采用改进了的稳定组合钻具以及合理的钻进工艺施工,提高了成孔率和钻孔见煤率,满足了穿层孔保直钻进施工的需要。

煤矿井下保直钻进技术及应用

介绍了煤矿井下保直钻进技术,根据施工煤矿的岩层性质和钻探设备,采用优选和设计的保直稳定组合钻具,通过穿层孔保直钻进试验,大幅提高了成孔质量和成孔率,较好地解决了钻孔严重偏斜的问题。

小倾角穿层钻孔的保直钻进研究

卧龙湖煤矿各主采煤层均为突出煤层,煤与瓦斯突出工作面回采前需施工穿层钻孔进行区域消突。根据现场调查和数据分析,在1011机巷底抽巷施工的穿层钻孔存在一定的偏差,尤其是小倾角钻孔与设计位置相差较远。针对钻孔存在偏差控制不到位的问题,该矿通过选用特殊施工组合、控制钻进过程中给进压力和转速,有效地避免了小角度穿层钻孔偏斜过大问题,消除了后期煤巷掘进和工作面回采期间的突出危险性,保证了矿井的正常接替,取得了较好的经济效益,解决了小角度穿层钻孔施工过程中的保直钻进的难题。

起伏薄煤层顺层孔工艺研究

我国南方地区的煤层赋存条件复杂,煤层较薄,倾角变化大,常规钻进工艺无法有效完成工作面顺层孔施工要求,存在抽采空白带。为了消除肥田矿111601工作面抽采盲区,在111601工作面进行顺层孔施工工艺试验研究。试验采用扶正器保直钻具组合和定向钻进2种施工工艺,根据钻孔轨迹分析了偏移规律及煤层赋存条件。现场试验表明,单一的保直钻具组合无法满足消除抽采盲区的目的;定向钻进工艺能通过分支孔施工,适应煤层起伏,使钻孔从一侧覆盖整个工作面宽度,有效消除了工作面中部抽采盲区,对于后续该工作面抽放钻孔施工具有指导作用。

煤矿巷道掘进长距离快速超前钻探工艺策略及配套机具研究

随着我国煤炭资源开采深度的逐步增加,地质条件和围岩环境日趋复杂,掘进时面临水害、瓦斯等灾害的程度日益增大,超前钻孔作为探查和治理灾害的必要通道,日益严重的采掘失衡对长距离快速超前钻探技术的需求极为迫切。首先,结合煤矿安全相关规程和煤矿巷道掘进工况,分析了巷道掘进对于超前钻探的需求。然后,根据“长距离快速超前钻探”的要义,分析了目前钻探工艺技术存在的“复杂地层钻孔深度不足”“钻孔偏斜严重”“硬岩钻进效率低”3个关键技术问题。其次,针对3个关键技术问题总结研究了“复杂跟管钻进技术”“钻孔防偏技术”“硬岩高效钻进技术”。针对复杂地层因钻孔坍塌难以成孔的难题,总结了不同护孔技术及配套机具,分析了其对于不同工况的适用性,开发了孔底驱动快速跟管成套机具,将复杂地层钻孔深度延长2~3倍;针对回转钻进工况下的超前探孔防偏难题,分析了回转钻进偏斜的力学机理,从抑制钻孔倾角和方位角的角度分析了防偏钻具的原理、结构以及性能,研发了能够同时稳定倾角和方位角的单动式保直钻具,钻进过程中外管不转、芯轴带动钻头旋转破岩,现场试验表明能够同时将倾角和方位角偏斜率控制在1.5(°)/100 m;针对硬岩巷道超前钻探存在的效率低、破岩刀具磨损快等问题,分析了不同硬岩高效破岩机理并综合阐述了对应的破岩机具及配套技术与装备,研制了基于主动抑振原理的小直径稳压提速钻具,在岩石坚固性系数f为12的煤系石灰岩地层中提速1.5~2倍。最后,针对超前探钻孔“护孔”“防偏”“提速”3个关键需求,提出了相应工艺机具的发展方向。

煤矿井下近水平钻孔大直径套管长距离下放技术

孔口套管封孔是后续钻孔施工与安全保障的基础,大直径套管通过能力、套管孔段轨迹偏斜控制和钻孔排渣效果是影响煤矿井下近水平钻孔大直径套管长距离下放成功的关键。为了提高套管近水平长距离下的成功率,建立了大直径套管刚性模型和弹性模型,获得了煤矿井下常用Φ178 mm、Φ146 mm和Φ127 mm套管在弯曲钻孔的通过能力数据;分析了近水平大直径套管孔段排渣困难与易发生偏斜的原因,提出采用大直径螺旋钻杆与内凹式PDC钻头进行保直钻进和高效排渣的技术方案,开发了相关钻具,制定了钻具组合,并分析了保直钻进和高效排渣机理。在赵固一矿进行了现场试验,完成3个钻孔施工,与常规工艺相比,套管孔段施工时间由110班次缩短至21班次,轨迹偏斜仅为0.042°/m,套孔下放成功率达到100%,有效解决了大直径套管近水平长距离下放难题。

下套管技术在井下定向探放水孔中的应用

下套管是煤矿井下定向探放水钻孔施工中非常重要的一项工作,是后续定向钻进及放水能否安全、顺利实施的关键。结合工程实例,通过对下套管技术原理进行分析,提出相应的技术措施,形成一整套行之有效的下套管技术及配套钻具,为今后类似工程施工提供借鉴。

定向钻孔孔口段成孔技术在阳泉矿区的应用

针对在煤矿井下长钻孔施工过程中,对定向钻孔孔口段的施工不够重视,尤其对超深套管(≥100 m)的安设,往往因孔口段钻孔轨迹偏移或套管脱扣等原因导致套管下不到位,造成钻孔报废、工期延长或材料浪费的情况,通过分析孔口段常见事故原因,提出了优化后的一整套先导孔及扩孔钻具保直成孔技术,解决了孔口段成孔技术问题。根据阳泉矿区工程实践应用证明,优化后的工艺应用效果良好且经济实用。

煤矿井下定向钻孔超长套管下放技术

针对煤矿井下定向钻孔超长套管下放成功率低、速度慢的问题,提出开孔段保直钻进、造斜段曲率控制、钻机驱动主动钻杆下放及套管导正等改进技术措施。在阳泉新景矿进行了现场试验,完成了3个满足煤矿井下水力压裂要求的定向钻孔超长套管下放,最大下深达到168 m,套管下放成功率达到100%,下套管平均工效由5.5 m/h最大提高至13.1 m/h,有效地解决了定向钻孔超长套管下放受限的难题。

影响煤矿井下钻孔施工轨迹的几点因素分析

本文从理论上分析影响井下钻孔施工轨迹的几点因素,并结合钻孔施工经验及实际状况,提出提高钻孔保直钻进效果的几种措施。

笏山金矿抢险救援6号钻孔快速准确中靶施工技术

笏山金矿发生事故后,我单位按应急救援指挥部的要求施工了6号救援钻孔。针对该矿区花岗岩硬度高,地层岩石破碎,以及地层含水丰富等特点,从设备安装到施工工艺及操作流程,制定了一套完整的施工技术方案。从而避免了误工误时,避免了救援过程中次生事故的发生。全孔采用气动潜孔锤钻进,合理调整钻进参数,不但解决了花岗岩地层进尺慢、钻效低的问题,还确保了钻孔一次性进入预定靶区,施工中做到了“稳、准、快”,最终圆满完成了救援孔的施工任务。

大直径钻井中钻具组合扶正器的选择及使用

大直径瓦斯抽放钻孔、电缆孔、通风孔、下料孔等特殊工程钻孔在煤矿安全生产中越来越广泛的应用,这些钻孔一般对落点要求严格,必须打到指定位置。防止钻孔弯曲的主要手段是通过限制钻进过程中钻具弯曲实现的,钻具弯曲的原因主要为钻具的挠曲变形,通过分析扶正器的位置对挠曲变形的影响,从而正确设置防斜钻具组合中扶正器位置,并通过正确选择扶正器的直径及外形,已达到钻孔保直的效果。

小角度穿层深孔偏移规律研究与控制技术应用

平宝公司主采煤层为突出煤层,煤与瓦斯突出工作面回采前需施工穿层钻孔进行区域消突。根据现场调查和数据分析,在己_(15-17)-12110采面抽放巷施工的穿层钻孔存在一定的偏差,尤其在小角度钻孔与设计位置相差较远。针对钻孔存在偏差控制不到位的问题,勘探工程处打钻工区通过对小角度钻孔的偏移规律研究,通过加装扶正器、控制钻进速度,可有效地减少小角度穿层钻孔偏斜过大问题,能够实现穿层深孔全覆盖精准施工,以确保瓦斯治理效果,保证采面月产不低于20万t,实现矿井安全高效发展。

Glutamate reduces experimental intestinal hyperpermeability and facilitates glutamine support of gut integrity

AIM:To assess whether glutamate plays a similar role to glutamine in preserving gut wall integrity.METHODS:The effects of glutamine and glutamate on induced hyperpermeability in intestinal cell lines were studied.Paracellular hyperpermeability was induced in Caco2.BBE and HT-29CL.19A cell lines by adding phorbol-12,13-dibutyrate(PDB) apically,after which the effects of glutamine and glutamate on horseradish peroxidase(HRP) diffusion were studied.An inhibitor of glutamate transport(L-trans-pyrrolidine-2,4-dicarboxylic acid:trans-PDC) and an irreversible blocker(acivicin) of the extracellular glutamine to glutamate converting enzyme,γ-glutamyltransferase,were used.RESULTS:Apical to basolateral HRP flux increased significantly compared to controls not exposed to PDB (n=30,P<0.001).Glutamine application reduced hyperpermeability by 19%and 39%in the respective cell lines.Glutamate application reduced hyperpermeability by 30%and 20%,respectively.Incubation of HT29CL.19A cells with acivicin and subsequent PDB and glutamine addition increased permeability levels.Incubation of Caco2.BBE cells with trans-PDC followed by PDB and glutamate addition also resulted in high permeability levels.CONCLUSION:Apical glutamate-similar to glutaminecan decrease induced paracellular hyperpermeability.Extracellular conversion of glutamine to glutamate and subsequent uptake of glutamate could be a pivotal step in the mechanism underlying the protective effect of glutamine.

Multiparty Quantum Secret Sharing of Secure Direct Communication Using Teleportation

We present an （n, n） threshold quantum secret sharing scheme of secure direct communication using Greenberger-Horne-Zeilinger state and teleportation. After ensuring the security of the quantum channel, the sender encodes the secret message directly on a sequence of particle states and transmits it to the receivers by teleportation. The receivers can recover the secret message by combining their measurement results with the sender＇s result. Ira perfect quantum channel is used, our scheme is completely secure because the transmitting particle sequence does not carry the secret message. We also show our scheme is secure for noise quantum channel.

Comparative outcome of stapled trans-anal rectal resection and macrogol in the treatment of defecation disorders

AIM:To prospectively assess the eff icacy and safety of stapled trans-anal rectal resection(STARR) compared to standard conservative treatment,and whether preoperative symptoms and findings at defecography and anorectal manometry can predict the outcome of STARR.METHODS:Thirty patients(Female,28;age:51 ± 9 years) with rectocele or rectal intussusception,a defecation disorder,and functional constipation were submitted for STARR.Thirty comparable patients(Female,30;age 53 ± 13 years),who presented with symptoms of rectocele or rectal intussusception and were treated with macrogol,were assessed.Patients were interviewed with a standardized questionnaire at study enrollment and 38 ± 18 mo after the STARR procedure or during macrogol treatment.A responder was def ined as an absence of the Rome Ⅲ diagnostic criteria for functional constipation.Defecography and rectoanal manometry were performed before and after the STARR procedure in 16 and 12 patients,respectively.RESULTS:After STARR,53% of patients were responders;during conservative treatment,75% were responders.After STARR,30% of the patients reported the use of laxatives,17% had intermittent anal pain,13% had anal leakage,13% required digital facilitation,6% experienced defecatory urgency,6% experienced fecal incontinence,and 6% required re-intervention.During macrogol therapy,23% of the patients complained of abdominal bloating and 13% of borborygmi,and 3% required digital facilitation.No preoperative symptom,defecographic,or manometric finding predicted the outcome of STARR.Post-operative defecography showed a statistically significant reduction(P < 0.05) of the rectal diameter and rectocele.The postoperative anorectal manometry showed that anal pressure and rectal sensitivity were not significantly modified,and that rectal compliance was reduced(P = 0.01).CONCLUSION:STARR is not better and is less safe than macrogol in the treatment of defecation disorders.It could be considered as an alternative therapy in patients unresponsive to macrogol.

The impact of foreign trade and FDI on environmental pollution

Over the past 30 years China＇s economy has made tremendous development and going on the road of opening-up is an important aspect of the successful experience, which should be unswervingly adhered to in the further. However, rationally looking at how different the impact of foreign economic activities on China＇s economy and society is economic workers＇ main task. From 1982 to 2006, based on six categories of China＇s environmental indicators, the paper improves the entropy method to calculate the environmental pollution index which can represent China＇s overall environmental situation, uses the VAR model of the impulse response function and variance decomposition method to study the impact of foreign trade, FDI on China＇s environmental pollution in the long-term. The results show that, FDI and import trade is conducive to the improvement of the quality of our environment and export trade is the deterioration of our environment, ＂pollution haven＂ hypothesis is proved in China. Export trade is an important variable that aggravates environmental pollution.

Sphincter-preserving R0 total mesorectal excision with resection of internal genitalia combined with pre-or postoperative chemoradiation for T4 rectal cancer in females

AIM: To evaluate the impact of chemoradiation admi- nistered pre- or postoperatively on prognosis in females following R0 extended resection with sphincter- preserving total mesorectal excision (TME) for locally advanced rectal cancer and to assess the association between chemoradiation and intra- and postoperative variables. METHODS: Twenty-one females were treated for locally advanced but preoperatively assessed as primarily resectable rectal cancer involving reproductive organs. Anterior resection with TME and excision of internal genitalia was combined with neo- or adjuvant chemoradiation. Two-year disease-free survival analysis was performed with the Kaplan-Meier method and log- rank test. The association between chemoradiation and other variables was evaluated with the Fisher’s exact test and Mann-Whitney test. RESULTS: Survival rate decreased in anaemic females (51.5% vs 57.4%), in patients older than 60 years (41.8% vs 66.7%) with poorly differentiated cancers (50.0% vs 55.6%) and tumors located ≤ 7 cm from the anal verge (42.9% vs 68.1%) but with the lack of importance. Patients with negative lymph nodes and women chemoradiated preoperatively had significantly favourable prognosis (85.7% vs 35.7%; P= 0.03 and 80.0% vs 27.3%; P = 0.01, respectively). Preoperative chemoradiation compared to adjuvant radiochemotherapy was not significantly associated with the duration of surgery, incidence of intraoperative bowel perforation and blood loss ≥ 1 L, rate of postoperative bladder and anorectal dysfunction, and minimal distal resection margin. It significantly influenced minimal radial margin (mean 4.2 mm vs 1.1 mm; P < 0.01). CONCLUSION: Despite involving internal genitalia, long-term disease-free survival and sphincter preservation may be achieved with combined-modality therapy for females with T4 locally advanced rectal carcinoma. Neoadjuvant chemoradiation does not compromise functional results and may significantly improve oncological outcomes probably due to enhanced radial clearance.

Investigation on complementarity between total mesorectal excision and radical resection in relation to postoperative local recurrence in patients receiving anus-reserve operation on rectal cancer

Objective:To investigate the difference and complementarity between total mesorectal excision(TME)and radical resection in relation to postoperative local recurrence in patients receiving anus-reserve operation on rectal cancer.Methods:Clinical data of 81 cases during a period from 1975 to 2001 were retrospectively analyzed.Results:In the 81 cases with local recurrence,49 of them laid to anastomosis and mesorectum,17 lymph nodes and 15 multi-site relapse.The choice of operative procedure included abdominoperineal resection in 58 cases,Hartmann’s operation in 4 cases,simple double-pelvic stoma in 12 cases,exploration in 7 cases,and total pelvic or rear-pelvic resection in combination with other organs in 6 cases. The rate of resection was 84.0%(68/81).32 cases reached clinical radical degree,and the rate of radical resection was 39.5% (32/81).The 5-year survival rate was 34.4%(11/32).Conclusion:Based on actual condition of the patients,attention to radi- cal resection and total mesorectal excision are necessary,and reasonable adoption of the operative procedure could reduce the local recurrence of rectal cancer.

Freshening of the intermediate water of the South China Sea between the 1960s and the 1980s

Variation in intermediate water salinity in the South China Sea (SCS) between the 1960s and 1980s was studied using historical hydrographic data. The results demonstrate that the water was significantly fresher in the 1980s than in the 1960s, indicating that vertical mixing at intermediate water depth was reduced in the 1980s. This was partially because of the change of the SCS meridional overturning circulation (MOC) connecting local intermediate water with deep water. Data assimilation showed a 0.5Sv (1 Sv=10 6m 3/s) reduction in the strength of the MOC, which is about one third of the mean SCS MOC. Because the SCS MOC is linked to the Pacific Ocean, such an interdecadal variation in the intermediate water SCS may reflect anthropogenic climate change in the world ocean.