标准编号:	GB/T 41029-2021
中文名称:	石油天然气钻井海洋弃井作业规程
英文名称:	Specification for offshore well abandonment operation of oil & gas drilling
中标分类:	E13    石油钻井
行业分类:	GB    国家标准
ICS分类:	75.020 75.020    石油和天然气的开采与加工 75.020
发布机构:	国家市场监督管理总局 国家标准化管理委员会
发布日期:	2021-12-31
实施日期:	2022-7-1
标准状态:	现行
翻译语言:	英文
文件格式:	PDF
中文字符数:	11000 字
翻译价格(元):	770.00 元
交付时间:	付款后 1~3 个工作日

1 Scope

This document establishes the requirements for well abandonment operating procedures and information management in offshore oil and gas exploration and development operations.

This document applies to oil and gas operations in the internal waters of the People's Republic of China. Territorial waters, contiguous zone, exclusive economic zone, continental shelf and other waters under the jurisdiction of the People's Republic of China for oil and gas exploration and development operations. It may also be used for operations in waters outside the PRC.

2 Normative references

The contents of the following documents constitute essential provisions of this document through the normative references in the text. Among them, note the date of the reference documents, only the date of the corresponding version applicable to this document; do not note the date of the reference documents, its latest version (including all the revision of the list) applicable to this document.

GB/T19139 Test methods for oil well cements

3 Terminology and definitions

The following terms and definitions apply to this document.

3.1

well residuum on seabed

An object left on the seabed (or bottom of a body of water in the case of inland waters) above the mud surface near the wellhead after well abandonment operations have been completed.

3.2

abnormal well

An oil and gas well that meets one or more of the following conditions, depending on its final state prior to disposal:

a) Gas wells and wells with a gas to oil ratio exceeding 350 (m'/m2 ) in standard conditions;

b) Wells with corrosive fluids such as H2S or CO2 in the formation and which are susceptible to corrosion after abandonment;

c) Wells with a maximum formation pore pressure equivalent density greater than 1.30 g/cm'.

4 General requirements, principles and procedures for well abandonment operations

4.1 General requirements

4.1.1 Prior to well abandonment operations. The integrity of the well pad shall be assessed and remedial measures shall be taken if the integrity requirements are not met.

4.1.2 After well abandonment operations, the formation and other permeable formations shall be effectively sealed so that the formation fluids between different pressure regimes cannot interfere with each other and there shall be at least two levels of barrier to ensure that there is no leakage of formation fluids to the subsea mud surface.

4.1.3 Casing and annular voids that have not achieved effective cement containment should not be used as a barrier for permanent well abandonment.

4.1.4 The first cement plug in the shot hole section, in the casing above the bare eye or above the tail pipe suspender shall be probed for cement plug topping and pressure tested to pass.

4.1.5 The last cement plug in the permanent abandonment well shall be not less than 50 m in length and the top surface of the plug shall be located 4 m to 30 m below the mud surface of the seabed.

4.1.6 When a cement plug is used to seal the flow channel between the oil, gas and water permeable layers in a permanently abandoned well, the length of the individual cement plug shall not be less than 50 m. In the case of oil, gas and water permeable layers in large-slope wells and horizontal wells, the length of the cement plug shall not be less than 50 m. The vertical height of the cement plug above the top of the water permeable layer shall not be less than 30 m.

4.1.7 When permanently abandoning a well in a water town within the territorial sea, all casing, piles, etc. shall be cut 4 m deeper than the mud surface of the sea floor.

4.2 Temporary well abandonment operation procedures

4.2.1 Completion of exploratory wells by casing or tailbore injection

4.2.1.1 Cement plugs or drillable bridge plugs shall be injected and cemented within 15 m above the top of each set of injection sections and poured to seal the oil and gas layer. A drillable bridge plug shall be placed within 15 m above the top hydrocarbon layer, pressure tested and a cement plug of not less than 30 m in length shall be placed on top of it. When the layer spacing is short, the cement shall be poured on top of the bridge plug when using the drillable bridge plug for sealing.

4.2.1.2 For special wells, the length of the cement plug shall not be less than 30 m when sealing between oil and gas formations with cement injection; when the layer spacing is short, the top of the plug shall be poured with cement when sealing with a drillable bridge plug. A drillable plug should be placed within 15 m above the top oil and gas layer. Pass the test pressure and inject a cement plug of not less than 50 m in length on the bridge plug, probe the top surface of the cement plug and pass the test pressure.

4.2.1.3 In the inner casing with effective cement seal in the annulus, inject a cement plug of not less than 50 m in length upwards (the length of the cement plug in this location should not be less than 100 m for special wells) and probe the top surface of the cement plug. The cement plug should be located close to the surface casing shoe.

4.2.1.4 When keeping the wellhead above the water surface, after completing the last - abandoned well cement plugging operation, take anti-corrosion and anti-freeze mopping measures above the cement plug as needed; when keeping the wellhead below the water surface, a wellhead cap or protective cap for the mudline suspension should be installed, and anti-corrosion measures can be taken as needed. Anti-hydrate and other measures.

4.2.1.5 abandonment of the well end, should be set up wellhead markers and safety protection facilities.

4.2.1.6 At the end of the temporary well abandonment, documentation of the well abandonment operation shall be filed and reported to the competent administrative authorities.

4.2.2 Exploration wells completed with bare eye or bare eye screen tubing

4.2.2.1 Depending on well conditions, fill the bare-hole section or screen tubing with completion or drilling fluid to protect the reservoir.

4.2.2.2 Seal a drillable bridge plug within 30m above the top packer of the casing shoe or screen tubing in the bare hole and test the plug with a cement plug of not less than 30m in length. Special wells should be filled with a cement plug of not less than 50m in length. The top surface of the cement plug shall be explored and tested for pressure.

4.2.2.3 In the inner casing with an effective cement seal in the annulus, inject a cement plug of not less than 50m in length upwards, preferably close to the surface casing shoe, and probe the top surface of the cement plug. Special wells shall have a drillable bridge plug seated at this location, pressure tested and filled with a cement plug of not less than 50 m in length.

4.2.2.4 Follow up operations shall be completed in accordance with 4.2.1.4.4.2.1.5.4.2.1.6.

4.2.3 Development wells

4.2.3.1 Wells drilled in abnormally pressurised sections, or wells not shot after cementing under casing (or tail pipe) in oil and gas sections shall be fully pressure tested and the wellhead shall be fitted with a wellhead device that can monitor wellhead pressure and provide pressure access. A retrievable bridge plug shall be installed and pressure tested at the subsea wellhead.

4.2.3.2 Injected wells or bare-hole completion wells, it is recommended that the production tubing column is lowered, a recovery tree is installed and the wellhead device is pressure tested, or that at least two formation fluid control barriers are achieved by placing a bridge plug, injecting a cement plug and installing a temporary wellhead. Refer to 4.2.1.4.2.2 for other well conditions.

4.2.3.3 Follow up operations are to be completed in accordance with 4.2.1.4.4.2.1.5 and 4.2.1.6.

4.3 Protocols for permanent well abandonment operations

4.3.1 Casing or tailbore completion of exploratory wells

4.3.1.1 Inter-stratigraphic sealing of oil and gas formations

The top surface of the cement plug should not be lower than 30m above the shot hole section. If the layer spacing is short, the cement plug can be injected continuously to seal multiple layers; for special wells, it is advisable to put a bridge plug between layers and continue to inject cement plugs upwards to seal them.

4.3.1.2 Plugging of top oil and gas layers

4.3.1.2.1 The cement return height of the uppermost oil and gas layer should not be lower than 50 m above the top of the injection section, and the top surface of the cement plug should be explored and pressure tested; or the bridge plug should be placed within 15 m above the top of the uppermost injection section. Pass the test pressure, and inject a cement plug of not less than 50 m in length on the bridge plug.

4.3.1.2.2 In special wells, it is advisable to place a cement squeeze packer within 15 m above the top injection section and to squeeze cement into the oil and gas reservoir by means of a test squeeze injection or intermittent cement squeeze, the amount of which shall be sufficient to seal the injection section or the maximum squeeze pressure to reach the original formation rupture pressure in that section. After cementing, a cement plug of not less than 50 m in length shall be injected into the cement packer, the top surface of the plug shall be probed and the plug shall be pressure tested.

4.3.1.3 Tail pipe hangers. Grading hoop blocking

Inject a cement plug with a length of not less than 60 m upwards at a point approximately 30 m below the tail pipe suspension and grading hoop.

4.3.1.4 Plugging of the upper pipe section

4.3.1.4.1 In the inner casing near the shoe depth of the surface casing and with an effective cement seal in the annulus, inject a cement plug of not less than 50 m in length upwards, probe the top surface of the plug and confirm.

4.3.1.4.2 Special wells shall be sealed with a bridge plug in the inner casing near the shoe depth of the surface casing and with an effective cement seal in the annulus, and after passing the pressure test, a cement plug of not less than 50 m in length shall be injected into it and the top surface of the plug shall be inspected and confirmed.

4.3.1.5 Upper casing recovery

Cut and recover the casing and casing head. See 4.1.7 for the required depth of cut for the last layer of casing.

4.3.1.6 Casing cutout sealing

Cement plugs are to be injected upwards at least 30 m below the cut-out position of each layer of casing that has been cut, with the cement plugs covering upwards to at least 30 m above the cut-out position.

4.3.1.7 Subsea Wellhead removal

In accordance with the relevant regulations of the administrative authority of the marine area.

4.3.1.8 Documentation

Upon completion of the permanent abandonment of the well, information shall be submitted for record in accordance with the requirements of the competent administrative authority.

4.3.2 Exploration wells completed with bare eye or bare eye screen tubing

4.3.2.1 Inter-layer sealing of oil and gas formations

4.3.2.1.1 In exposed borehole sections, the permeable layers of oil, gas and water shall be fully sealed by drilling a cement plug at least 50 m above them to seal the permeable layers of oil, gas and water to prevent interflow or outflow from the seafloor. If there is no oil, gas or water in the exposed section of the borehole, a cement plug is drilled in the last - . At least 30 m of cement plugs should be placed below and above the last - .

4.3.2.1.2 In bare borehole sieve tube sections, if well conditions permit, seal the bare borehole section by blocking it, or by sealing a cement squeeze packer within 30m above the top sieve tube packer, using a test squeeze injection. Intermittent cement squeezing is used to squeeze cement into permeable layers of oil, gas and water.

4.3.2.2 Plugging of the top oil and gas layer

4.3.2.2.1 Inject cement plug upwards near 30m below the top packer of the casing shoe or sieve pipe in the upper bare eye, the top surface of the cement plug should be 50m above the top packer of the casing shoe or sieve pipe, probe the top surface of the cement plug and test pressure to pass.

4.3.2.3 Follow-up operations

Follow up operations shall be completed in accordance with 4.3.1.3 to 4.3.1.8.

4.3.3 Development wells where the tubular column in the well can be recovered

4.3.3.1 Tubular column recovery

The well is pressurised and the downhole production tubulars are recovered.

4.3.3.2 Inter-layer sealing of bare-hole sections

Cement plugs should be used to seal the flow path between oil, gas and water permeable layers in a bare-hole section or in a bare-hole screened tubular section, with a single plug length of not less than 50m. When sealing oil, gas and water layers with cement plugs, they shall be covered from 30 m below the bottom of the blocked oil, gas and water layer upwards to not less than 30 m above the top of the blocked layer.

4.3.3.3 Inter-layer sealing of the shot hole section

4.3.3.3.1 Cement plugs shall be injected in sections from not less than 30 m below the bottom of each group of injection sections upwards, with the top surface of the cement plugs being not less than 30 m above the top of each group of injection sections.

4.3.3.3.2 When mining or injecting with a layered pipe column but with short layer spacing, the layered pipe column may be closed. The top of the cement plug should be no less than 30m above the top of the blocked section.

4.3.3.4 Plugging of the top oil and gas layer

4.3.3.4.1 The cement return height for sealing the top oil, gas and water layer shall be not less than 50m above the top of the layer to be sealed, and the top surface of the cement plug shall be explored and pressure tested to pass.

4.3.3.4.2 Special wells should be sealed within 30m above the top of the oil and gas formation, the top casing shoe of the naked eye or the top packer of the screen pipe -. Only the cement squeeze packer should be used to squeeze cement into the formation using the test squeeze injection and intermittent squeeze cement method. After the cementing process is completed, a cement plug of not less than 50 m in length shall be injected into the cementing packer, the top surface of the cement plug shall be probed and tested for pressure.

4.3.3.5 Follow-up operations

Follow up operations are to be completed in accordance with 4.3.1.3 to 4.3.1.8.

4.3.4 Development wells where the production tubular column in the well cannot be fully recovered

4.4 Other well abandonment principles and requirements

4.4.1 Production well sections that are no longer in use should be abandoned in the same manner as a permanently abandoned well.

4.4.2 Abandoned well cement shall be tested and qualified in accordance with the requirements of GB/T19139.

4.4.3 The quality of the seating and sealing of the plug shall be ensured in the lower plug section and the cementing quality of the cement to the casing wall shall be ensured in the cemented section.

4.4.4 Before and after the floating drilling unit has completed the well abandonment operation, it is advisable to launch a remotely operated vehicle (ROV) to inspect and photograph the area around the wellhead (within a radius of 30m) and to map the remains of the wellhead on the sea floor.

4.4.5 Underwater inspection, photography and mapping of the subsea wellhead may be carried out when necessary after the well abandonment operation is completed by the jack-up or fixed drilling unit.

5 Well abandonment information and reporting

5.1 Well abandonment plan preparation

5.1.1 Exploratory well design

The exploratory well drilling design should include an abandonment design.

5.1.2 Overall oil and gas field development programme

The overall oil and gas field development programme shall include the well abandonment programme.

5.1.3 Well abandonment operation plan

A well abandonment plan shall be prepared and submitted to the competent administrative authority prior to operation. The plan shall include:

a) An assessment of the safety risks associated with well abandonment or wellhead removal.

b) The plan for abandoning the well or removing the wellhead remnants, operating procedures, schedule, well fluid properties, etc.

5.2 Well abandonment report preparation and collection

5.2.1 Collect and collate information on well abandonment operations and prepare an abandonment operation report.

5.2.2 The well abandonment report should include the following:

a) The name of the field/block and the geographical location of the sea area;

b) Well name and well location coordinates;

c) Water depth and elevation of the rotary core;

d) A summary of the well abandonment process, including the dates of abandonment, etc;

e) Well structure and casing dimensions for each layer and actual depth of penetration;

d) Cementing cement return height and pressure test data for each outer casing level:

g) Depth of each formation and the original pressure of the formation, section and depth of the shot hole;

h) Number of bridge plugs inserted, depth of insertion and pressure test data;

i) Number of cement plugs. Depth, length, density and pressure test data;

j) depth of casing cut in each layer;

k) Completion diagram of abandonment and debris removal operations;

l) Schematic diagram of the final well structure for the abandonment operation.

5.2.3 The abandonment report should be included and maintained in its entirety as part of the well history.

Foreword
1 Scope
2 Normative references
3 Terms and definitions
4 General requirements, principles and protocols for well abandonment operations
5 Well abandonment information and reports
bibliography

1范围
本文件规定了在海洋石油天然气勘探开发作业中弃井作业规程和资料管理的要求。
本文件适用于在中华人民共和国的内水.领海、毗连区、专属经济区、大陆架,以及中华人民共和国管辖的其他海域内进行的油气勘探开发作业等。在境外的水域作业亦可参照使用。
2规范性引用文件
下列文件中的内容通过文中的规范性引用而构成本文件必不可少的条款。其中,注日期的引用文件,仅该日期对应的版本适用于本文件;不注日期的引用文件,其最新版本(包括所有的修改单)适用于本文件。
GB/T19139油井水泥试验方法
3术语和定义
下列术语和定义适用于本文件。
3.1
海底井口遗留物well residuum on seabed
弃井作业结束后,遗留在海底(内水水域时为水体底部)井口附近泥面以上的物体。
3.2
特殊井abnormal well
根据油气井弃置前的最终状态,满足以下一个或一个以上条件的油气井:
a) 气井及 标准状态下气油比超过350(m'/m2 )的油井;
b) 地层含H2S,CO2等腐蚀性流体、弃井后易发生腐蚀的井;
c) 最大地层孔隙压力当量密度高于1.30 g/cm'的井。
4 弃井作业总体要求、原则及规程
4.1 总体要求
4.1.1 弃井作业前.应评估井简完整性,对不符合完整性要求的应采取补救措施。
4.1.2 弃井作业后,应有效封隔油气层和其他渗透性地层,使不同压力层系之间的地层流体不能相互窜通,应至少有两级屏障保证地层流体无泄漏到海底泥面的通道。
4.1.3没有达到有效水泥封隔的套管及环空不应作为永久弃井的隔离屏障。
4.1.4射孔段、裸眼以上套管内或尾管悬挂器上方第一个水泥塞应探水泥塞顶并试压合格。
4.1.5永久 弃井最后一个封隔水泥塞长度不应小于50 m,且水泥塞顶面位于海底泥面下4 m~30 m。
4.1.6永久弃井时,用水泥塞封堵油、气、水渗透层之间流动通道时,单个水泥塞长度不应少于50m;大斜度井及水平井的油、气.水渗透层顶部以上水泥塞垂直高度不应小于30 m.
4.1.7在领海以内水城永久弃井时,所有套管、桩等的切割位置应深于海底泥面4m。
4.2临时弃井作业规程
4.2.1套管或尾管射孔完成探井
4.2.1.1应在每组射孔段顶部以上15 m内注水泥塞或下人可钻式桥塞并倾倒水泥封隔油气层。顶部油气层以上15 m内应下人可钻式桥塞、试压合格并在其上注长度不少于30 m的水泥塞。层间距较短时,用可钻式桥塞进行封隔时桥塞顶部应倾倒水泥。
4.2.1.2对于特殊井,油气层间用注水泥封隔时水泥塞长度不应少于30m;层间距较短时,用可钻式桥塞进行封隔时桥塞顶部应倾倒水泥。顶部油气层以上15 m内应下可钻式桥塞.试压合格并在桥塞上注长度不小于50 m的水泥塞,探水泥塞顶面并试压合格。
4.2.1.3在环空有有效水泥封固的内层套管内,向上注长度不小于50m的水泥塞(特殊井此位置水泥塞长度不应小于100 m) ,探水泥塞顶面。水泥塞位置宜靠近表层套管鞋。
4.2.1.4在水面以上保留井口时,完成最后--个弃井水泥塞作业后,根据需要在水泥塞以上采取防腐、防冻揩施;在水面以下保留井口时,应装好井口帽或泥线悬挂器的防护帽,根据需要可采取防腐.防水合物等措施。
4.2.1.5弃井结束,应设置井口标志物和安全保护设施。
4.2.1.6临时弃井结束,应对弃井作业资料进行归档备案并向行政主管部门报告。
4.2.2裸眼或裸眼筛管完成探井
4.2.2.1根据井况,在裸眼井段或筛管内充填保护油气层的完井液或钻井液。
4.2.2.2在裸眼上层套管鞋或筛管顶部封隔器以上30m内坐封一只可钻式桥塞并试压合格,在桥塞上注长度不小于30m的水泥塞。特殊井应在桥塞上注长度不小于50m的水泥塞。探水泥塞顶面并试压合格。
4.2.2.3在环空有有效水泥封固的内层套管内,向上注长度不小于50m的水泥塞,水泥塞位置宜靠近表层套管鞋,探水泥塞顶面。特殊井应在此位置坐封一只可钻式桥塞,试压合格并在其上注长度不小于50 m的水泥塞。
4.2.2.4后续按 4.2.1.4.4.2.1.5.4.2.1.6的要求完成作业。
4.2.3开发井
4.2.3.1钻遇异常压力层段、油气层段下套管(或尾管)固井后未射孔的井应全井简试压合格,井口应安装可监控井口压力并能提供压井通道的井口装置。水下井口宜下人一个可回收式桥塞并试压合格。
4.2.3.2已射孔井或裸眼完成井宜下人生产管柱、安装采油树并对井口装置试压合格,或通过下桥塞、注水泥塞和安装临时井口等措施至少实现两道地层流体控制屏障。其他井况参照4.2.1.4.2.2执行。
4.2.3.3后续按照 4.2.1.4.4.2.1.5和4.2.1.6的要求完成作业。
4.3永久弃井作业规程
4.3.1套管或尾管射孔完成探井
4.3.1.1油气层层间封隔
自每组油气层底部以下不少于30m向上注水泥塞,水泥塞顶面应不低于射孔段以上30m,层间距较短时可连续注水泥塞--次性封隔多层;特殊井宜在层间下桥塞,并向上继续注水泥塞封隔。
4.3.1.2顶部油气层封堵
4.3.1.2.1最上部油气层的水泥返高不应低于射孔段顶部以上50 m,探水泥塞顶面并试压合格;或在最上部射孔段顶部以上15 m内下人桥塞.试压合格,并在桥塞上注长度不小于50 m的水泥塞。
4.3.1.2.2特殊井宜在 顶部射孔段以上15 m以内下人挤水泥封隔器,采用试挤注、间歇挤水泥的方法向油气层挤水泥,挤人量应满足封固射孔段或最高挤人压力达到该井段原始地层破裂压力。挤水泥结束后,应在挤水泥封隔器上注长度不小于50m的水泥塞,探水泥塞顶面并试压合格。
4.3.1.3尾管悬挂器 .分级箍封堵
在尾管悬挂器、分级箍以下约30 m处向上注长度不小于60 m的水泥塞。
4.3.1.4上部套 管段封堵
4.3.1.4.1在表层套管鞋深度附近且环空有有效水泥封固的内层套管内,向上注长度不小于50 m的水泥塞,探水泥塞顶面并确认。
4.3.1.4.2特殊井应在表层套管鞋深度附近且环空有有效水泥封固的内层套管内坐封一只桥塞,试压合格后在其上注长度不小于50m的水泥塞,探水泥塞顶面并确认。
4.3.1.5上部套管 回收
切割、回收套管和套管头。最后一层套管切割深度要求见4.1.7。
4.3.1.6套管割口封堵
在已切割的每层套管制口位置以下至少30 m处向上注水泥塞,水泥塞向上覆盖至切制位置以上至少30 m.
4.3.1.7海底 井口遗留物清除
按海区所属行政主管部门相关规定执行。
4.3.1.8资料备案
永久弃井结束后,应根据行政主管部门的要求提交资料备案。
4.3.2裸眼或裸眼筛管完成探井
4.3.2.1油气层层 间封隔
4.3.2.1.1在裸露井眼井段,对油、气、水等渗透层进行全封,在其 上部打至少50 m水泥塞,以封隔油、气水等渗透层,防止互窜或者流出海底。裸露井眼段无油、气、水时,在最后- .层套管鞋以下和以上各打至少30m水泥塞。
4.3.2.1.2在裸眼筛管井段,若井况允许可采用封隔裸眼井段的方式进行封堵,或者在筛管顶部封隔器以上30m内坐封一只挤水泥封隔器,采用试挤注.间歇挤水泥的方法向油、气、水等渗透层挤水泥。
4.3.2.2顶部油气层封堵
4.3.2.2.1在裸眼上层套管鞋或筛管顶部封隔器以下30m附近向上注水泥塞,水泥塞顶面应高出套管鞋或筛管顶部封隔器以上50m,探水泥塞顶面并试压合格。
4.3.2.3后续作业
后续按4.3.1.3~4.3.1.8的要求完成作业。
4.3.3井内管柱可以回收的开发井
4.3.3.1管柱回收
压井并起出井下生产管柱。
4.3.3.2裸眼段层间封隔
用水泥塞封堵裸眼井段或封隔裸眼筛管井段的油、气、水渗透层之间流动通道，单个水泥塞长度不应少于50m.用水泥塞封堵油、气.水层时,应自所封堵油、气、水层底部30m以下向上覆盖至所封堵层顶以上不少于30 m.
4.3.3.3射孔段层 间封隔
4.3.3.3.1自每组射孔段底部以下不少于30m向上分段注水泥塞,水泥塞顶面应高出每组射孔段顶部不少于30m.层间距较短时可连续注水泥塞-次性封隔多层;特殊井宜在层间下桥塞,并向上继续注水泥塞封隔。
4.3.3.3.2用分层管 柱开采或注人但层间距短时,可关闭分层管柱.上部滑套，一次性向下挤注水泥封堵相邻产层,水泥塞顶面应高出所封堵层段顶部不少于30m。
4.3.3.4顶部油气层封堵
4.3.3.4.1封固顶部油、气、水层的水泥返高应高于所封堵层顶部不少于50m,探水泥塞顶面并试压合格。
4.3.3.4.2特殊井宜在油气层顶部、裸眼上层套管鞋或筛管顶部封隔器以上30m内坐封-.只挤水泥封隔器,采用试挤注,间歇挤水泥的方法向油气层挤水泥,挤入量应满足封固油气层段要求或最高挤入压力达到该井段原始地层破裂压力。挤水泥结束后,在挤水泥封隔器上注长度不小于50 m的水泥塞,探水泥塞顶面并试压合格。
4.3.3.5后续作业
后续作业按4.3.1.3~4.3.1.8的要求完成作业。
4.3.4井内生产管柱不能全部回收的开发井
4.4其他弃 井原则及要求
4.4.1不再使用的生产 井段应按永久弃井方式弃置。
4.4.2弃井水泥应按照GB/T19139的要求检测合格。
4.4.3下桥塞井段应保证桥塞坐封质量,水泥封固井段应保证水泥与套管壁的胶结质量。
4.4.4浮式钻井装置完成弃井作业前后,宜分别下入遥控潜水器(ROV)对井口周围(半径30m内范围)检查、摄影以及绘制海底井口遗留物图。
4.4.5自升式或固定式钻井装置完成弃井作业后,必要时可进行水底检查、摄影以及绘制海底井口遗留物图。
5弃井资料和报告
5.1弃井计划编制
5.1.1探井设计
探井钻井设计应包括弃井设计。
5.1.2油气田总体开发方案
油气田总体开发方案应包括弃井方案。
5.1.3弃井作业计划书
作业前应编写弃井作业计划书,并向行政主管部门报备。计划书应包括:
a)弃井作业或者清除井口遗留物安全风险评估。
b)弃井或者清除井口遗留物施工方案、作业程序、时间安排、井液性能等。
5.2弃井报告编写与收存
5.2.1收集和整理弃井作业资料并编制弃井作业报告。
5.2.2弃井 作业报告应包括以下内容:
a) 油田/区块名称与所在海域地理位置;
b) 井名以及井位坐标;
c) 水深与转盘补心海拔高度;
d) 弃井作业过程概述,包括弃井作业起止日期等;
e) 井身结构和各层套管尺寸、实际下人深度;
D) 各层套管外各级固井水泥返高和试压数据:
g) 各组油气层深度以及油气层原始压力、射孔层段及深度;
h) 桥塞下人数量、下人深度及试压数据;
i) 水泥塞数量.深度、长度、密度及试压数据;
j) 各层套管切割深度;
k) 弃井、清除遗 留物作业完工图;
l) 弃井作业最终井身结构示意图。
5.2.3弃井作业报告作为井史的一部分内容,应完整收录和保存。