1、and Gas Production .V. , API TITLExVT-1 96 = 0732290 055b429 157 = American Petroleum Ins titute Introduction to Oil and Gas Production Exploration and Production Department BOOK ONE OF THE VOCATIONAL TRAINING SERIES FIFTH EDITION, JUNE 1996 I API TITLEsVT-1 9b 0732290 0556430 979 SPECIAL NOTES API
2、publications necessarily address problems of a general nature. With respect to par- ticular circumstances, local, state, and federal laws and regulations should be reviewed. API is not undertaking to meet the duties of employers, manufacturers, or suppliers to warn and properly train and equip their
3、 employees, and others exposed, concerning health and safety risks and precautions, nor undertaking their obligations under local, state, or fed- eral laws. Information concerning safety and health risks and proper precautions with respect to particular materials and conditions should be obtained fr
4、om the employer, the manufacturer or supplier of that material, or the material safety data sheet. Nothing contained in any API publication is to be construed as granting any right, by im- plication or otherwise, for the manufacture, sale, or use of any method, apparatus, or prod- uct covered by let
5、ters patent. Neither should anything contained in the publication be construed as insuring anyone against liability for infringement of letters patent. Generally, API standards are reviewed and revised, reaffirmed, or withdrawn at least ev- ery five years. Sometimes a one-time extension of up to two
6、 years will be added to this re- view cycle. This publication will no longer be in effect five years after its publication date as an operative API standard or, where an extension has been granted, upon republication. Status of the publication can be ascertained from the API Authoring Department tel
7、ephone (202) 682-8O. A catalog of API publications and materials is published annually and up- dated quarterly by API, 1220 L Street, N.W., Washington, D.C. 20005. This document was produced under API standardization procedures that ensure appro- priate notification and participation in the developm
8、ental process and is designated as an API standard. Questions concerning the interpretation of the content of this standard or comments and questions concerning the procedures under which this standard was devel- oped should be directed in writing to the director of the Authoring Department (shown o
9、n the title page of this document), American Petroleum Institute, 1220 L Street, N.W., Wash- ington, D.C. 20005. Requests for permission to reproduce or translate all or any part of the material published herein should also be addressed to the director. API publications may be used by anyone desirin
10、g to do so. Every effort has been made by the Institute to assure the accuracy and reliability of the data contained in them; however, the Institute makes no representation, warranty or guarantee in connection with this publi- cation and hereby expressly disclaims any liability or responsibility for
11、 loss or damage re- sulting from its use or for the violation of any federal, state, or municipal regulation with which this publication may conflict. API standards are published to facilitate the broad availability of proven, sound engi- neering and operating practices. These standards are not inte
12、nded to obviate the need for ap- plying sound engineering judgment regarding when and where these standards should be utilized. The formulation and publication of API standards is not intended in any way to in- hibit anyone from using any other practices. Any manufacturer marking equipment or materi
13、als in conformance with the marking re- quirements of an API standard is solely responsible for complying with all the applicable requirements of that standard. API does not represent, warrant, or guarantee that such prod- ucts do in fact conform to the applicable API standard. All rights reserved.
14、No part of this work may be reproduced, stored in a retrieval system, or transmitted by any means, electronic, mechanical, photocopying, recording or other- wise, without prior written permission from the publisher. Contact the Publishe6 API Publishing Services, 1220 L Street, N.W, Washington, D.C.
15、20005. Copyright Q 1996 American Petroleum Institute API TITLE*VT-II 96 = 0732290 055b43L 805 FOREWORD API publications may be used by anyone desiring to do so. Every effort has been made by the Institute to assure the accuracy and reliability of the data contained in them; however, the Institute ma
16、kes no representation, warranty, or guarantee in connection with this publication and hereby expressly disclaims any liability or responsibility for loss or damage resulting from its use or for the violation of any federal, state, or municipal regulation with which this publication may conflict. Sug
17、gested revisions are invited and should be submitted to the director of the Exploration and Production Affairs Department, American Petroleum Institute, 1220 L Street, N.W., Washington, D.C. 20005. iii API TITLEaVT-1 96 O732290 0556432 741 CONTENTS Page SECTION 1-ORIGIN AND ACCUMULATION OF OIL AND G
18、AS 1.1 Introduction 1 1.2 Organic Theory of Origin 1 1.3 Accumulation and Occurrence 1 1.4 Oil and Gas Segregation . 2 1.5 Reservoir Rock . 3 1.6 Geologic Types of Reservoirs . 3 1.7 Types of Production Processes 5 1.7.1 Gas Drive Reservoirs 6 1.7.2 Water Drive Reservoirs 6 SECTION 2-THE WELL 2.1 In
19、troduction 9 2.2 Casing . 2.3 Completion Methods 10 2.5 Safety Valves . 9 2.4 Tubing . 10 12 SECTION 3-WELL TREATMENT 3.2 Fracturing 3.4 Chemical Treatment . 17 3.5 Sand Control . 18 3.1 Introduction 17 17 3.3 Acidizing 17 3.6 Frac Packing 18 SECTION “THE WELLHEAD 4.1 Introduction 19 4.2 Thecasinghe
20、ad . 19 4.4 The Christmas Tree 20 4.3 TheTubingHead 19 4.5 Subsea Trees . 22 SECTION 5-ARTIFICIAL LIFT 5.1 Introduction 25 5.2 Sucker Rod Pumping 25 5.3 Pump-off Controllers (POC) 27 5.4 GasLifting . 28 5.5 Subsurface Electrical Pumping 28 5.6 Subsurface Hydraulic Pumping . 29 5.7 Jet Pumps 29 SECTI
21、ON the well is drilled to these forma- tions. Pipe is then run into the hole to provide a conduit for the fluid to flow to the surface. Wells may be grouped into two relatively broad categories: straight holes and direction- ally drilled wells. Straight hole wells, shown in Figure 16, are those dril
22、led to targets essentially beneath the surface lo- cation of the well, although some small deviations in the well bore are likely to occur during the drilling process. Directionally drilled wells are those which are drilled to targets not directly beneath the surface location of the well. Directiona
23、lly drilled wells can be classified further into straight kick, S-kick, and horizontal wells. In straight kick wells, the well bore is deviated until the desired angle is achieved. This angle is then maintained all the way to the bottom of the hole as seen in Figure 17. In S-kick wells, the well bor
24、e is deviated to achieve the desired horizontal displacement and then returns to a vertical direction before penetrating the producing zone. The term “S-kick” is derived from the shape of the course that the well bore follows as seen in Figure 18. Horizontal wells, as the name implies, are those wel
25、ls that are deviated until the well bore achieves a horizontal direction. The well bore may then continue in the horizontal direction for hundreds or even thousands of feet, depending on the results desired as shown by Figure 19. For a further discussion of horizontal drilling, see Section 19. 2.2 C
26、asing A drilled hole must be stabilized to prevent freshwater sand contamination, lost circulation, hole sloughing, or charging shallow sands with abnormal pressures. To do this, successively smaller diameter casing strings are set in the well starting with the conductor pipe, then surface pipe, in-
27、 termediate string (if needed due to operational problems), and finally the production or oil string. The depth that each string is set is determined by the particular conditions at the well site. For example, surface casing can be set at depths from 200 to 5,000 feet and an oil string can be set fr
28、om depths of 2,500 to 25,000 feet or more. A sketch of a well is shown in Figure 20. Each time a casing string is set and Producina zone Figure 16-Straight Hole Well Figure 17-Straight Kick Well 9 API TITLE*VT-1 9b M O732290 0556444 463 W 10 Book One of the Vocational Training Series I Producing zon
29、e I I I I I I Figure 18-Kick Well brought to the surface, a blowout preventer (BOP) of appro- priate size and pressure rating is flanged onto the casing by a casinghead to control pressure in the drilling well. Casing must be designed to meet the physical conditions imposed on the pipe. A well with
30、10, psi surface pressure requires much heavier casing than a well with 2,000 psi surface pressure. By the same reasoning, the collapse resis- tance of the casing must be much higher for a string that is to be set at 20,000 feet than a string to be set at 2,000 feet. API has very carefully establishe
31、d specifications for size, grade, weight per foot, type of threaded connection, and length of each section (joint) of casing. Figure 21 shows the relative sizes of casing and tubing, various types of connec- tions identifying the threads on the casing, and a tabulation of common sizes of casing. Som
32、e of the connections are for specialized use. 2.3 Completion Methods There are many methods of preparing an oil well to produce. They are governed by the type of reservoir (see Section 1). If the well is completed in a hard formation, the oil-producing zone may be left entirely open, with no perfo-
33、rated casing or liner used to protect the hole. This is called an open-hole completion. In loose, soft sands, it may be neces- sary to cement the production string through the producing zone and use a slotted screen or a gravel pack in the produc- I i I Producing zone 3 4 Figure 19-Horizontal Well i
34、ng interval. One of the most common types of completion, shown in Figure 23, consists of setting the oil string or pro- duction casing through the producing formation, cementing it in place, and then perforating through the casing and cement into the producing formation. Other types of comple- tions
35、 are shown in Figures 22 and 24. Some completions are made using casing liners to extend the cased interval below an upper casing suing. Production liners are commonly sec- tions of smaller diameter casing that are run on a liner hanger (Figure 25) and cemented in place. This eliminates the need to
36、extend the smaller diameter production casing back to the surface. A schematic of a well using a casing liner is shown in Figure 20. A multiple completion is another process which allows production from different pay zones to be produced through the same wellbore. This affords a means of obtaining t
37、he maximum amount of oil with the minimum use of casing. Figure 26 shows how this is accomplished. 2.4 Tubing Because the casing and liner must remain in a weli for a long time and their repair or replacement would be costly, another smng of pipe is placed in the well through which the oil is usuall
38、y produced. This is called tubing. During the later life of the well, the same tubing may be used to accommo- date a downhole pump or other means of artificial lift. Tub- API TITLE*VT-II 9b = 0732270 055b445 3TT introduction to Oil and Gas Production 11 / Wing valve Swab valve Christmas Upper master
39、 vaive Lower master valve d F Perforations 1 i I I I ! I 1 I - / Annulus access valve Intermediate casing Production liner hanger Production packer Production liner II o n Figure 2-Simplified Diagrammatic Representation of a Weil Showing the Casing Strings, Production Tubing and Christmas Tree 12 Bo
40、ok One of the Vocational Training Series Shortcoupling casing joint Longcoupling casing joint API round thread casing Exiremeline casing API buitres thread casing 98 3a 7 23 8 OUTSIDE DIAMETER INCHES) Common Sizes of Casing Outside Internal Inches Ib. per foot Coiiapse,psi preSsre,p6i weight Resista
41、nceto Yieid 9.50 17 23 26.40 36 40 40.50 54.50 3310 4m 3290 3010 2740 2770 1730 1140 4380 5320 4360 4140 3930 3950 3130 2730 All sizes above are Grade K-55, seamless steel, thrraded and coupled API joint Other grades and weights of casing are available. Common lengths are: Range 2, from 25 ft to 34
42、ft, range 3.34 fi or more. Figure 21-Relative size of casing and tubing, types of casing connections, and common sizes of casing. I API TITLExVT-1 96 0732290 0556446 236 = ing sizes range from lY4 inch to 4 /2 inches in diameter. The tubing is suspended from the wellhead (surface) and usually reache
43、s to within a few feet of the bottom of the well. Tubing is also used as the flow smng because casing is usually too large to permit the well to flow efficiently or, in some cases, to maintain continuous flow. Tubing packers are sometimes used in the tubing string to seai off the space between the t
44、ubing and the production cas- ing. This is done particularly in wells where there are high reservoir pressures. By sealing off this space, the casing is not exposed to high pressure, and the chances of a casing failure are reduced. Tubing anchors and packers also support part of the weight of the tu
45、bing in the casing and prevent the tubing string from “working“ (moving up and down). One kind of tubing packer is shown in Figure 27. Occasionally it is both practical and economical to drill a smali-diameter hole and use conventional tubing as casing in completing the well. This is called a tubing
46、less completion since no reievable inner string of tubing is used to conduct fluids to the surface. The casing is cemented from bottom to surface and perforated opposite the producing interval. The equipment used is essentially the same as a conventional well, including a float collar, guide shoe wi
47、th back pressure valve, and landing nipple as shown in Figure 28. Tubingless completions with pipe as small as 2 /s-inch outside diameter provide for well control, well stimulation, sand control, workover, and an artificial lift system. 2.5 Safety Valves When a well is first put on production, it us
48、ually flows be- cause of pressure in the reservoir. Often wells are located where an accident could cause danger to the environment, people, or facilities. To provide needed protection, there are several types of safety valves used to shut in the weil in case of an accident or equipment failure in a
49、reas where accidents could occur. One type is a subsurface valve which will close off when a predetermined rate of flow is exceeded An alter- nate type is the surfacetontrolled subsurface safety valve that is actuated by an external hydraulic pressure system. This valve is shown in Figure 29. Both of these types of safety valves are installed in the tubing string, commonly at depths of 100 to 200 feet beneath the sea floor, or at similar depths beneath the ground surface when installed in onshore wells. Another commonly used type of safety valve is installed on the well
